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Model Taxonomy

This chapter provides a comprehensive guide to the model landscape as of August 2026, covering model families, capabilities, and selection criteria for production systems.

Last verified: August 15, 2026. The model landscape evolves rapidly. Always cross-check with provider pricing pages and release notes.

August 2026 headline: Most of the month's releases were post-training refreshes or derivatives rather than new pretraining runs, and no US frontier lab shipped a new flagship base model. The action moved to prices, licenses, and access control. The clear exception is Alibaba's Qwen3.8-Max, a genuinely new 2.4T base whose weights landed August 12. Claude Sonnet 5's introductory $2/$10 per 1M became the permanent price on August 10, and the scheduled September 1 rise to $3/$15 was canceled, making Sonnet 5 permanently cheaper than the Sonnet 4.6 it replaced. Running the other way, DeepSeek raises V4 prices 3x to 12x effective August 16 at 16:00 UTC, moving to peak and off-peak billing (off-peak is exactly half peak, and peak covers only 01:00-04:00 and 06:00-10:00 UTC). That ends its run as the unambiguous cheap option. OpenAI shipped GPT-5.6-Cyber (August 10, $12.50/$75 per 1M) behind a new two-tier Daybreak Blue and Daybreak Red access program, the most concrete production example yet of capability-tiered gating. Google released Gemini 3.7 Flash (August 13) at half price through year-end, and SpaceXAI released Grok 4.6 (August 12) with a 500K context. On open weights the licensing picture split: Alibaba's Qwen3.8-Max (August 12, 2.4T/95B active) shipped under a bespoke commercially gated license while its Qwen3.8-27B sibling (August 14) shipped plain Apache 2.0, Meta returned to open weights with Muse Glimmer (August 10, 30B, Apache 2.0), and Z.ai withheld GLM-5.3's weights pending safety evaluation after cyber capability grew faster than expected. Claude Opus 4.1 retired on August 5, closing out the last $15/$75 Opus tier. Benchmark figures throughout this section are largely vendor-reported; confirm on independent leaderboards.

July 2026 headline: Anthropic shipped a full generation refresh: Claude Sonnet 5 (June 30, claude-sonnet-5, new default everywhere, introductory $2/$10 per 1M through August 31 then $3/$15) and Claude Opus 5 (July 24, claude-opus-5, unchanged $5/$25 with an optional Fast mode at $10/$50 about 2.5x faster). Claude Fable 5 was restored globally July 1 after the export-control suspension, with a new jailbreak-specific cybersecurity classifier; Mythos 5 returned only to roughly 100 US critical-infrastructure organizations via Project Glasswing. GPT-5.6 (Sol, Terra, Luna) reached general availability July 9, and on July 30 OpenAI cut Luna 80% to $0.20/$1.20 and Terra 20% to $2/$12 (Sol stays $5/$30). The open-weight frontier had its strongest month ever: Moonshot Kimi K3 (July 16, weights July 27) is the largest open-weight model to date at 2.8T total / 104B active with a 1M context, and Thinking Machines Lab debuted Inkling (July 15, 975B / 41B active, open weights), the leading US open-weights model. Google shipped Gemini 3.6 Flash, 3.5 Flash-Lite, and a government-gated 3.5 Flash Cyber (July 21) while delaying Gemini 3.5 Pro. Meta Muse Spark 1.1 (July 9) arrived with Meta's first paid self-serve model API ($1.25/$4.25 per 1M). Black Forest Labs announced FLUX 3 (July 23), a unified image, video, audio, and action model, in gated early access. Benchmark figures across these launches are largely vendor-reported; confirm on independent leaderboards.

June 2026 headline: Anthropic released Claude Fable 5 (June 9, claude-fable-5, $10/$50 per 1M, 1M context), its most capable widely released model: a Mythos-class model made safe for general availability, with an Opus 4.8 fallback safeguard on sensitive topics. Claude Mythos 5 ships the same day as the unrestricted variant for Project Glasswing partners, succeeding Mythos Preview at less than half its price.

June 10-26 update: A dense second wave of June launches followed. Google DeepMind DiffusionGemma (June 10, Apache 2.0) is Google DeepMind's first open-weight text-diffusion model: a 26B Mixture-of-Experts (~4B active) that denoises blocks of tokens in parallel for roughly 4x faster generation on a single H100, trading some quality versus standard Gemma 4. Gemini 3.5 Live Translate (June 9, built on Gemini 3 Pro) added real-time speech-to-speech translation across 70+ languages in public preview via the Gemini Live API and AI Studio. Cohere North Mini Code 1.0 (June 9, Apache 2.0) is Cohere's first open coding model, a 30B / 3B-active MoE that runs on one H100. Moonshot Kimi K2.7 Code (June 12, Modified MIT) tunes K2.6 for long-horizon software work (1T / 32B-active MoE, roughly 30% fewer thinking tokens). Z.ai GLM-5.2 (coding-plan access June 13, open weights under MIT June 16-17) is a 744B / 40B-active MoE with a 1M context that reports SWE-Bench Pro 62.1, ahead of GPT-5.5 on that benchmark, at roughly $1.40 / $4.40 per 1M. xAI Grok Imagine Video 1.5 reached general availability June 16 (image-to-video with synchronized audio, $0.080 per second of video), and Grok 4.3 arrived on Amazon Bedrock June 15 ($1.25 / $2.50 per 1M, xAI's first model there). Alibaba's official Qwen Cloud changelog lists a June snapshot adding vision to Qwen 3.7-Max (text-only at its May launch), though some independent coverage attributes that vision update to Qwen 3.7-Plus instead, so verify before relying on it. Separately, on June 12 Anthropic suspended access to Claude Fable 5 and Claude Mythos 5 following a US export-control directive, with Mythos 5 later cleared for a limited set of US institutions. Then on June 26, OpenAI previewed GPT-5.6 (Sol, Terra, and Luna), its next-generation line, in a limited release to a small set of US-government-approved partners over dual-use cybersecurity concerns, echoing the Anthropic restriction; Sol claims a new Terminal-Bench 2.1 record and Terra targets GPT-5.5-level quality at about half the cost. Coding scores here are largely vendor-reported; confirm on independent leaderboards.

May 2026 recap: Anthropic Claude Opus 4.8 (May 28, same $5/$25 price as Opus 4.7; Dynamic Workflows research preview with hundreds of parallel subagents; fast mode at $10/$50 is 3x cheaper than the Opus 4.7 fast mode); OpenAI GPT-5.5 (April 23) and GPT-5.5 Instant (May 5, default in ChatGPT); Claude Opus 4.7 (April 16, GA on Bedrock/Vertex/Foundry); Google Gemma 4 (April 2, Apache 2.0) and Gemini 3.2 Flash (quiet rollout May 5); DeepSeek V4 Pro and V4 Flash (April 24; 75% V4 Pro discount made permanent May 22, new list price $0.435/$0.87 per 1M from June 1); Moonshot Kimi K2.6 (April 20, 1T MoE / 32B active); Alibaba Qwen 3.6 Plus / 3.6-35B-A3B / 3.6 Max-Preview; Mistral Medium 3.5 (April 29, unified chat/reasoning/coding/vision); Meta Muse Spark (April 8, first closed-weight Meta model); Llama 4 Behemoth release paused through fall 2026 amid capability concerns. SWE-bench Verified published leaders before the Fable 5 launch: Claude Mythos Preview 93.9%, GPT-5.5 88.7%, Claude Opus 4.8 88.6%; ARC-AGI-2 leader: GPT-5.5 at 85.0%. Anthropic describes Fable 5 as state of the art on nearly all tested benchmarks; standard numeric scores were not in the launch post, so verify on the leaderboards.

Table of Contents​


Model Categories​

By Capability Level (April 2026 Reality)​

TierCharacteristicsExamplesUse Case
FrontierState-of-the-art reasoning, agentic masteryClaude Fable 5, Claude Opus 4.8, GPT-5.5, Gemini 3.1 Pro, Grok 4.3Complex reasoning, coding, production agents
Fast/EfficientSub-200ms, cost-optimizedGemini 3.1 Flash, GPT-5.5-mini, Claude Haiku 4.5, DeepSeek V4 FlashHigh-volume streaming, UI, real-time
Battle-TestedMature, widely-deployed, stableClaude Sonnet 4.6, GPT-5.5 Instant, Gemini 3.1 ProEnterprise production workloads
Small/EdgePrivate, edge, specializedLlama 4 Scout, Mistral Small 4, Phi-4Local privacy, on-device, MoE-efficient
Reasoning-HeavyExtended internal CoTClaude Opus 4.8 (thinking), GPT-5.5 reasoning, Gemini 3.1 Pro Deep Think, DeepSeek-R1Math, code debug, multi-step logic

By Reasoning Mode (2025–2026)​

ModeCapabilityModelsUse Case
StandardFast, intuitive responseGPT-5.5-mini, Claude Sonnet 4.6Chat, simple extraction
Extended ThinkingInternal scratchpad CoT before outputClaude Opus 4.8, GPT-5.5 reasoning, DeepSeek-R1Math, code debugging, planning
HybridUser-controllable reasoning depthClaude Opus 4.8, GPT-5.5Variable complexity tasks

Frontier Models (June 2026)​

Claude Opus 5 (Anthropic) - July 2026 NEW​

AttributeValue
Model IDclaude-opus-5
Context Window1M tokens (default and max; 128K max output)
Input / Output Cost$5.00 / $25.00 per 1M (unchanged from Opus 4.8)
Fast mode$10.00 / $50.00 per 1M, about 2.5x faster
BenchmarksAnthropic's launch post, reporting the pre-release benchmark it called Frontier-Bench v0.1 (since renamed Terminal-Bench 3.0): 43.3% at max effort vs GPT-5.6 Sol's 34.4%, Fable 5's 33.7%, and Opus 4.8's 18.7%. Within 0.5% of Fable 5 on CursorBench 3.2 at about half the cost per task; roughly 3x the next-best model on ARC-AGI 3. Vendor-reported.
ReleasedJuly 24, 2026 (Claude API, Claude Code, Claude Cowork; new default on Claude Max)

What it is: The Opus line's generational successor at unchanged pricing, aimed at long-horizon agentic coding and computer use. Beta features include mid-conversation tool changes and automatic fallback routing. The dual-price Fast mode continues the pattern Opus 4.8 introduced: one model, two latency tiers.

Best for: Agentic coding and computer-use workloads where Fable 5's ceiling is not needed; the price-performance flagship of the Claude line as of late July 2026.

Claude Sonnet 5 (Anthropic) - July 2026 NEW​

AttributeValue
Model IDclaude-sonnet-5
Context Window1M tokens per third-party coverage (not stated in the launch post)
Input / Output Cost$2.00 / $10.00 per 1M (permanent since August 10, 2026)
Cache / BatchCache write $2.50 per 1M (5 min) or $4.00 (1 hr); cache hit $0.20; Batch API $1.00 / $5.00
PositioningThe most agentic Sonnet yet: planning, browser and terminal tool use, autonomous operation approaching Opus 4.8 at lower cost
Safety postureCyber safeguards on by default; deliberately reduced cybersecurity capability relative to Opus-class models
ReleasedJune 30, 2026 (default model across consumer and developer products same day)

What it is: The new production workhorse, replacing Sonnet 4.6 as the default. On August 10, 2026 Anthropic made the introductory $2/$10 rate permanent and canceled the September 1 increase to $3/$15, so Sonnet 5 is permanently cheaper than the Sonnet 4.6 it succeeds (still $3/$15). Cost models built on the reversion assumption should be revised down.

Best for: Production agent fleets, coding at scale, and the default tier in cost-aware routing stacks.

Claude Fable 5 (Anthropic) - June 2026 NEW​

AttributeValue
Model IDclaude-fable-5
Context Window1M tokens (Opus 4.7 tokenizer; roughly 30% more tokens than pre-4.7 models for the same text)
Max Output128K tokens
Input Cost$10.00 / 1M tokens
Output Cost$50.00 / 1M tokens
ThinkingAdaptive thinking, always on (no separate extended-thinking toggle)
MultimodalText + Vision (new state of the art on vision tasks per Anthropic)
BenchmarksState of the art on nearly all tested benchmarks per Anthropic; highest frontier score on Cognition's FrontierCode, highest on the Hebbia Finance Benchmark, ViBench, and CursorBench. Standard numeric scores (SWE-bench, GPQA) were not published in the launch post.
ReleasedJune 9, 2026 (GA on Claude API, Claude Platform on AWS, Amazon Bedrock, Vertex AI, Microsoft Foundry)

What it is: A Mythos-class model made safe for general availability. Until now the Mythos line (SWE-bench Verified 93.9% on Mythos Preview) was restricted to ~11 Project Glasswing partners over dual-use cybersecurity concerns. Fable 5 brings that capability tier to everyone by pairing it with conservative safeguards.

The Opus 4.8 fallback safeguard: When Fable 5's classifiers detect a request in one of three categories (offensive cyber techniques, bioweapon-adjacent biology and chemistry, or attempts to distill the model), the response is silently delegated to Claude Opus 4.8 and the user is informed. Anthropic says this triggers in under 5% of sessions and is deliberately tuned conservative, so some harmless requests get caught. Architecturally this is a production example of model-tier routing as a safety control, not just a cost control.

Best for: The most demanding reasoning, long-horizon agentic work, vision-heavy tasks, and workloads where capability ceiling matters more than unit cost. Anthropic reports it sustains autonomous operation longer than any previous Claude model.

Considerations: 2x the per-token price of Opus 4.8 ($10/$50 vs $5/$25), so route only ceiling-bound work to it. Mythos-class traffic carries a 30-day data retention requirement (not used for training; access-logged; deleted after 30 days in almost all cases), which matters for compliance reviews. On subscription plans it was included at no extra cost June 9-22, then moved to usage credits. There is no Fable-tier fast mode or published cache/batch discount at launch; check the pricing page.

Claude Mythos 5 (Anthropic) - RESTRICTED ACCESS​

AttributeValue
Model IDclaude-mythos-5
StatusLimited availability: Project Glasswing partners and select biology researchers
RelationshipSame underlying model as Fable 5 with safeguards lifted in some areas
Pricing$10 / $50 per 1M (less than half of Mythos Preview)
ReleasedJune 9, 2026

Why it matters: Succeeds Claude Mythos Preview at comparable or somewhat stronger capability and much lower price. The Fable/Mythos split formalizes a two-track release pattern: one safeguarded general release, one unrestricted release for vetted defenders.

Claude Opus 4.8 (Anthropic) - May 2026​

AttributeValue
Context Window1M tokens (standard pricing across the full window)
Input Cost$5.00 / 1M tokens (same as 4.7)
Output Cost$25.00 / 1M tokens (same as 4.7)
Cache: 5m write$6.25 / 1M tokens
Cache: 1h write$10.00 / 1M tokens
Cache: hit / refresh$0.50 / 1M tokens
Batch API$2.50 / $12.50 per 1M (50% discount)
Fast mode (research preview)$10 / $50 per 1M (about 2.5x faster; 3x cheaper than the Opus 4.7 fast mode which was $30 / $150)
Extended ThinkingNative, adaptive mode
MultimodalText + Higher-resolution Vision
SWE-bench Verified88.6%
SWE-Bench Pro69.2% (up from 64.3% on Opus 4.7)
Terminal-Bench 2.174.6% (GPT-5.5 still leads at 78.2%)
GDPval-AA1890 Elo (up from 1753 on Opus 4.7)
OSWorld-Verified82.3%
Online-Mind2Web84%
ReleasedMay 28, 2026 (GA on Claude API, AWS Bedrock, Vertex AI)

Best for: Long-running autonomous coding work in Claude Code, codebase-scale migrations, agentic workflows that need parallel subagents, and workloads where the alignment and honesty gains matter.

Key features over Opus 4.7:

  • Dynamic Workflows (research preview): Claude plans the work and runs hundreds of parallel subagents in a single Claude Code session, verifies their outputs, and reports back. Suited for codebase-scale migrations across hundreds of thousands of lines.
  • Mid-task system messages: The Messages API now accepts system messages mid-conversation, useful for steering long agent runs without ending the session.
  • Optional fast mode at roughly 2.5x speed for $10 / $50 per 1M, priced 3x lower than the Opus 4.7 fast mode.
  • Effort-control toggle in claude.ai and Cowork lets users tune reasoning depth per turn.
  • Expanded Claude Code rate limits.

Considerations: Tokenizer is the same one introduced in Opus 4.7 (up to 35% more tokens than the pre-4.7 tokenizer for the same fixed text). GPT-5.5 still holds the SWE-Bench Verified leaderboard at 88.7% and leads Terminal-Bench 2.1 at 78.2%. GPQA Diamond slipped 0.6 pts versus Opus 4.7. Anthropic's tokenizer change means token counts and bills for the same text are not directly comparable to pre-4.7 models. There was no Claude Sonnet 4.8; the line jumped to Claude Sonnet 5 on June 30, 2026, which replaced Sonnet 4.6 as the production workhorse.

[!NOTE] Retired August 5, 2026: claude-opus-4-1-20250805 was removed from the Claude API, closing out the last $15/$75 per 1M Opus tier. Every first-party Anthropic Opus SKU is now $5/$25 (or $10/$50 in Fast mode). The model remains available on Amazon Bedrock and Google Cloud, which set their own retirement schedules, so code pinned to that ID fails on the first-party API while still working on the partner clouds.

Claude Opus 4.7 (Anthropic)​

AttributeValue
Context Window1M tokens
Max Output128K tokens
Input Cost$5.00 / 1M tokens (same as 4.6)
Output Cost$25.00 / 1M tokens (same as 4.6)
Extended ThinkingNative, Adaptive mode
MultimodalText + Higher-resolution Vision
SWE-bench Verified (Adaptive)87.6% (May 13, 2026)
ReleasedApril 16, 2026 (GA on API, Bedrock, Vertex, Microsoft Foundry)

Best for: Autonomous coding agents (powers Claude Code), multi-file refactors, complex reasoning. Same pricing as 4.6 - straight upgrade for most workloads. Considerations: Use Sonnet 4.6 for cost-sensitive workloads; Opus 4.7 mainly for tasks requiring peak coding/agentic quality.

Claude Mythos Preview (Anthropic) - SUCCEEDED BY MYTHOS 5​

AttributeValue
StatusRestricted research preview, Project Glasswing partners only (~11 orgs: AWS, Apple, Cisco, Google, Microsoft, NVIDIA, Palo Alto, etc.)
Reason for restrictionDual-use cybersecurity capabilities
SWE-bench Verified93.9% (May 13, 2026; the published SOTA before the Fable 5 / Mythos 5 launch)
ReleasedApril 7, 2026 (restricted partner preview); succeeded by Claude Mythos 5 on June 9, 2026 at less than half the price

Best for: Historical reference. Its capability tier reached general availability as Claude Fable 5 on June 9, 2026; new Glasswing work should target Mythos 5.

Claude Opus 4.6 (Anthropic)​

AttributeValue
Context Window1M tokens
Max Output128K tokens
Input Cost$5.00 / 1M tokens
Output Cost$25.00 / 1M tokens
Extended ThinkingNative adaptive thinking (configurable budget_tokens)
MultimodalText + Vision
HighlightsMost capable Anthropic model; exceptional coding and reasoning
ReleasedFebruary 2026

Best for: Most complex reasoning, autonomous software engineering, agentic workflows. Considerations: Premium pricing; use Sonnet 4.6 for tasks that don't need peak capability.

Claude Sonnet 4.6 (Anthropic)​

AttributeValue
Context Window1M tokens
Input Cost$3.00 / 1M tokens
Output Cost$15.00 / 1M tokens
Extended ThinkingSupported
MultimodalText + Vision
HighlightsHandles tasks previously requiring Opus tier; best cost/quality balance
ReleasedFebruary 2026

Best for: Production coding agents (powers Claude Code), complex reasoning at scale. Considerations: Now covers most Opus-level tasks at lower cost. Strong default for most workloads.

GPT-5.4 (OpenAI)​

AttributeValue
Context Window272K tokens (standard); extended available
Input Cost$2.50 / 1M tokens
Output Cost$15.00 / 1M tokens
MultimodalText, Vision, native computer use
HighlightsBuilt-in computer-use capabilities; 33% fewer factual errors vs GPT-5.2; combines coding + agentic strengths
ReleasedMarch 2026

Best for: Agentic workflows with computer use, coding, professional tasks. Considerations: Long-context pricing doubles at 272K+ tokens.

GPT-5.4-mini (OpenAI)​

AttributeValue
Context Window272K tokens
Input Cost$0.75 / 1M tokens
Output Cost$4.50 / 1M tokens
HighlightsBest cost/performance for high-volume GPT-5 tier workloads
ReleasedMarch 2026

Best for: High-volume API calls, cost-optimized reasoning, production chatbots.

GPT-5.4 Pro (OpenAI)​

AttributeValue
Context Window272K tokens
Input Cost$30.00 / 1M tokens
Output Cost$180.00 / 1M tokens
HighlightsMaximum reasoning power; premium tier for hardest tasks
ReleasedMarch 2026

Best for: Competition-level math, complex multi-step reasoning. Considerations: Very expensive; use standard GPT-5.4 or mini for volume.

GPT-5.6 Sol / Terra / Luna (OpenAI) - GA July 9, 2026​

AttributeValue
VariantsSol (flagship), Terra (balanced), Luna (fast, low cost)
Context Window1M tokens (all three); 128K max output; knowledge cutoff February 16, 2026
Sol pricing$5.00 / $30.00 per 1M
Terra pricing$2.00 / $12.00 per 1M (cut 20% from $2.50/$15 on July 30)
Luna pricing$0.20 / $1.20 per 1M (cut 80% from $1/$6 on July 30)
Reasoning"max" reasoning effort plus an "ultra" mode that uses subagents to accelerate complex work
API features at GAProgrammatic tool calling, multi-agent support, explicit prompt-cache breakpoints
BenchmarksSol: 53.6 on Agents' Last Exam (13.1 points ahead of Claude Fable 5) and a Terminal-Bench 2.1 record. Claude Fable 5 still leads SWE-Bench Pro (80 vs Sol's 64.6), a benchmark OpenAI publicly disputes. Vendor-reported.
ReleasedLimited preview June 26, 2026; general availability July 9, 2026

What it is: OpenAI's next-generation flagship line, shipped for the first time as three models. The June 26 preview was gated at the request of the US government over dual-use cybersecurity capability; GA followed a 13-day review. The three-tier structure plus the steep July 30 cuts (Luna at $0.20/$1.20 is priced against open-weight competition) reset the routing math for anyone doing tiered model selection.

Best for: Sol for frontier agentic work and cybersecurity-adjacent coding; Terra as the GPT-5.5-class production default at roughly half GPT-5.5's price; Luna for high-volume classification, extraction, and routing tiers.

GPT-5.6-Cyber (OpenAI) - August 2026 NEW (restricted)​

AttributeValue
Model IDgpt-5.6-cyber
Context Window400K total (272K max input, 128K max output)
Input / Output Cost$12.50 / $75.00 per 1M; cached input $1.25
AccessDaybreak Red tier only, with identity verification, legal attestations, and approved use cases. Responses API only. Hardware security keys become mandatory on individual Daybreak accounts from September 1, 2026
Refusal postureTrained for a lower refusal rate on dual-use security work: 95.0% completion on OpenAI's internal Advanced Cybersecurity Completion Rate eval versus 1.5% for GPT-5.6 Sol
ReleasedAugust 10, 2026 (the Daybreak Blue and Red tier split appears in the API changelog dated August 7)

What it is: A cybersecurity model built on GPT-5.6 Sol, shipped alongside a split of the Daybreak program into two tiers. Daybreak Blue gives approved defenders access to general-purpose frontier models for vulnerability discovery, secure code review, detection engineering, and incident response. Daybreak Red is separately approved and gates gpt-5.6-cyber for vulnerability reproduction, exploit validation, penetration testing, and red teaming.

Why it matters architecturally: This is the clearest production instance of capability-tiered gating to date. A model that is deliberately more permissive than the frontier default, priced at 2.5x Sol, restricted to a single API surface, and fenced behind identity verification plus mandatory hardware 2FA is a reference design for how labs are operationalizing dual-use access. Compare with Anthropic's Fable 5 and Mythos 5 split and Google's Gemini 3.5 Flash Cyber: three labs, three variations on the same tiering pattern.

GPT-5.5 (OpenAI) - May 2026 NEW​

AttributeValue
Context Window1M tokens
Input Cost$5.00 / 1M tokens
Output Cost$30.00 / 1M tokens
MultimodalText, Image, Audio, Video
ARC-AGI-285.0% (May 13, 2026 - leader)
ReleasedApril 23, 2026

Best for: Highest-quality multimodal workloads; current ARC-AGI-2 leader. Pitched as "new class of intelligence for real work" - replaces GPT-5.4 for top-tier reasoning + multimodal. Considerations: ~2× the input cost of GPT-5.4 ($2.50 → $5.00) and ~2× output ($15 → $30). Use GPT-5.5 Instant for chat workloads where the price isn't justified.

GPT-5.5 Instant (OpenAI) - May 2026 NEW​

AttributeValue
StatusDefault in ChatGPT and chat-latest in API since May 5, 2026
Hallucination Reduction52.5% fewer on high-stakes prompts (medicine/law/finance) vs GPT-5.3 Instant
AIME 202581.2% (up from 65.4% on GPT-5.3 Instant)
Response Length~30% fewer words/lines than predecessor
ReleasedMay 5, 2026

Best for: Default ChatGPT-equivalent workloads, instant chat, high-stakes domains where hallucination reduction matters. Considerations: Replaces GPT-5.3 Instant as the chat default. GPT-5.2-chat-latest and GPT-5.3-chat-latest deprecated May 8, 2026.

GPT-Realtime-2, Translate, Whisper (OpenAI) - May 2026 NEW​

AttributeValue
CapabilityRealtime voice with GPT-5-class reasoning
Translate Coverage70+ input → 13 output languages
Pricing$32 / $64 per 1M audio tokens (input/output)
ReleasedMay 7, 2026

Best for: Real-time voice agents, multilingual translation, voice-first products. Realtime API Beta was removed May 12, 2026 - Realtime-2 is the supported path.

Gemini 3.1 Pro (Google)​

AttributeValue
Context Window1M tokens
Input Cost$2.00 / 1M tokens (standard); $4.00 (200K+)
Output Cost$12.00 / 1M tokens (standard); $18.00 (200K+)
MultimodalNative: Text, Vision, Audio, Video
HighlightsState-of-the-art Google reasoning; powerful agentic and coding capabilities
ReleasedFebruary 2026

Best for: Complex reasoning, multimodal analysis, long-context workloads. Considerations: Replaced Gemini 3 Pro Preview. Gemini 2.5 Pro/Flash deprecated June 2026.

Gemini 3.1 Flash (Google)​

AttributeValue
Context Window1M tokens
Input Cost$0.10 / 1M tokens
Output Cost$3.00 / 1M tokens
MultimodalNative: Text, Vision, Audio, Video
HighlightsFastest Google model; best price/performance for high-volume
ReleasedMarch 2026

Best for: Real-time multimodal apps, high-volume pipelines, long-context RAG.

Gemini 3.2 Flash (Google) - May 2026 NEW​

AttributeValue
StatusQuiet rollout in iOS Gemini app and Google AI Studio May 5, 2026 (no formal announcement yet)
ReleasedMay 5, 2026

Best for: Likely successor to 3.1 Flash for high-volume workloads. Treat as preview - pricing and full capability disclosure pending official launch.

Gemini Deep Research / Deep Research Max (Google) - May 2026 NEW​

AttributeValue
Built onGemini 3.1 Pro
CapabilitiesMCP support; native chart/infographic generation; extended test-time compute; async background workflows
ReleasedApril 21, 2026

Best for: Research agents, document synthesis, long-running async workflows. The MCP support makes it the first Google research-agent product with first-class tool integration.

Gemini Robotics-ER 1.6 (Google DeepMind) - May 2026 NEW​

AttributeValue
DomainPhysical robotics, embodied reasoning
New capabilityReading gauges/sight glasses
DeploymentBoston Dynamics Spot
ReleasedApril 14, 2026

Best for: Robotics applications requiring vision-language grounding for physical actions. Available via Gemini API and AI Studio.

Gemini 3.7 Flash (Google) - August 2026 NEW​

AttributeValue
Model IDgemini-3.7-flash
Context Window1,048,576 tokens in / 65,536 out
Input / Output Cost$0.75 / $3.75 per 1M through December 31, 2026, then $1.50 / $7.50. Context caching $0.075 per 1M; Batch $0.375 / $1.875
MultimodalText, image, audio, video; first Gemini model with agentic video processing on by default
Knowledge cutoffMarch 2026
ReleasedAugust 13, 2026 (GA)

What it is: Google's workhorse tier, built on Gemini 3.6 Flash with what the model card describes as algorithmic improvements to the reasoning foundation rather than a new pretraining run. Customizable thinking configurations trade quality against cost and latency per request. Google-reported gains over 3.6 Flash include FrontierCode 1.1 Main 43.6% versus 34.4% and WebDev Arena Elo 1588 versus 1538.

Considerations: The half-price introductory rate expires December 31, 2026 and then doubles, so run cost models against the January 2027 numbers before committing to volume. Gemini 3.5 Pro still has not shipped as of mid-August; gemini-3.1-pro-preview remains Google's top Pro-tier entry.

Grok 4.6 (SpaceXAI) - August 2026 NEW​

AttributeValue
Model IDgrok-4.6
Context Window500K tokens
Input / Output Cost$2.00 / $6.00 per 1M below a 200K prompt; $4.00 / $12.00 at or above 200K. Cached input $0.50
ReasoningEffort settings low, medium, high (default), xhigh
Knowledge cutoffFebruary 1, 2026
ReleasedAugust 12, 2026

What it is: SpaceXAI's frontier model, focused on long-running agents and interactive visual work. Artificial Analysis Intelligence Index 61, up from 56 for Grok 4.5 High.

Two traps worth knowing. The higher long-prompt rate applies to all tokens in the request once the prompt reaches 200K, not just the tokens past the threshold. And cached input got more expensive than Grok 4.5 ($0.50 versus $0.30 per 1M), so cache-heavy agent loops do not automatically get cheaper on the upgrade. Note the vendor name: xAI completed a rebrand to SpaceXAI, so current docs and release notes use the new name.

Grok 4 (xAI)​

AttributeValue
Context Window256K tokens
Input Cost$3.00 / 1M tokens
Output Cost$15.00 / 1M tokens
HighlightsNative tool use and real-time search; competitive reasoning
ReleasedJuly 2025 (Grok 4.20 beta: February 2026)

Best for: Live web research, reasoning-heavy tasks, real-time X/web integration. Considerations: Grok 4.1 Fast available at $0.20/$0.50 for high-volume.

Model Comparison: Frontier Tier (June 2026)​

ModelReasoningCodingContextAgenticCost
Claude Fable 5★★★★★★★★★★★★★★★★★★★★$$$$$
Claude Mythos 5 (restricted)★★★★★★★★★★★★★★★★★★★★$$$$$
Claude Opus 4.8★★★★★★★★★★★★★★★★★★★★$$$$
Claude Opus 4.7★★★★★★★★★★★★★★★★★★★★$$$$
GPT-5.5★★★★★★★★★★★★★★★★★★★★$$$$
Claude Opus 4.6★★★★★★★★★★★★★★★★★★★★$$$$
GPT-5.4★★★★★★★★★★★★★★★★★★★$$$
Claude Sonnet 4.6★★★★★★★★★★★★★★★★★★★★$$$
Gemini 3.1 Pro★★★★★★★★★★★★★★★★★★$$
Grok 4★★★★★★★★★★★★★★★★$$$
GPT-5.4-mini★★★★★★★★★★★★★★★$
Gemini 3.1 Flash★★★★★★★★★★★★★★$
GPT-5.5 Instant★★★★★★★★★★★★★★★★$$

Production Heritage & Maturity​

While frontier models lead on benchmarks, many enterprise systems rely on battle-tested models:

Model FamilyProduction SinceMaturity Note
GPT-4oMay 2024Most mature ecosystem; lowest latency variance; highest rate limits.
Claude 3.5 Sonnet / 3.7 SonnetJune 2024Gold standard for tool-use reliability and structured output.
Gemini 2.5 ProMarch 2025Proven at scale; stable long-context. Being deprecated June 2026 in favor of 3.x.
o1 / o3Sept 2024Well-understood reasoning model failure modes; o3 superseded o1.

Why stay on "older" frontier models?

  1. Consistency: New models have "release-window" latency spikes and behavior shifts.
  2. Cost Efficiency: Previous generation is often 50-80% cheaper after a new release.
  3. Guardrail Tuning: Security and moderation layers are more refined.

Open Source Models​

Llama 4 Family (Meta) -- NEW April 2026​

ModelParametersContextArchitectureNotes
Llama 4 Scout17B active / 16 experts (MoE)10MSparse MoEIndustry-leading 10M context; fits single H100; beats Gemma 3, Gemini 2.0 Flash-Lite
Llama 4 Maverick17B active / 128 experts (MoE)1MSparse MoEBeats GPT-4o and Gemini 2.0 Flash; comparable to DeepSeek V3 at half active params
Llama 4 Behemoth~288B active (est.)-Dense MoEStill training; outperforms GPT-4.5, Gemini 2.0 Pro on STEM benchmarks

Strengths:

  • First Llama generation with Mixture-of-Experts architecture
  • Natively multimodal from the ground up (text, image, video input)
  • Open weights on Hugging Face; available via Meta AI on WhatsApp, Messenger, Instagram
  • Scout's 10M token context window is industry-leading for open models

Llama 3.x Family (Meta) -- Previous Generation​

ModelParametersContextLicenseNotes
Llama 3.3 70B70B128KLlama 3.3Still widely deployed; strong general model
Llama 3.1 405B405B128KLlama 3.1Largest dense Meta model; being superseded by Llama 4

Note: Llama 3.x remains widely used in production, but Llama 4 Scout/Maverick offer superior performance with lower active parameter counts thanks to MoE.

DeepSeek Family​

ModelParametersContextStatusNotes
DeepSeek V4 Pro1.6T total / 49B active (MoE)1MGAPreviewed April 24, 2026. Uses ~27% compute / 10% memory of V3.2 at 1M tokens. SWE-bench Verified 80.6%. NIST CAISI evaluation (May 2026) places it ~8 months behind US frontier (Elo ~800). Open weights on Hugging Face. API: $0.435 / $0.87 per 1M input/output (75% discount made permanent May 22, 2026, effective June 1). Cache-hit input $0.003625/M.
DeepSeek V4 Flash284B total / 13B active (MoE)1MGASmaller-active variant for high-throughput workloads. API: $0.14 / $0.28 per 1M (cache-hit $0.0028/M). Cheapest frontier-class 1M-context API as of May 2026.
DeepSeek-V3.2671B (MoE)128KFrontierGeneral-purpose; 98% cache-hit discount ($0.28/$0.42 per 1M base). Largely superseded by V4 Flash for new builds.
DeepSeek-V3671B (MoE, 37B active)128KFrontierGPT-4o level at a fraction of training cost; open weights.
DeepSeek-R1671B (MoE)128KReasoningMatches o1 on math/code; first open-source reasoning model.
DeepSeek-R1-Distill7B–70B-ReasoningDistilled to smaller models; cost-efficient reasoning.

Key May 2026 context: DeepSeek V4 Pro (released April 24, with the 75% promotional discount made permanent on May 22) closed the gap with US frontier models on multiple benchmarks at a fraction of the cost. At $0.435 / $0.87 per 1M, V4 Pro is roughly 10x cheaper than Claude Opus 4.7 ($5 / $25) and 5-10x cheaper than GPT-5.5 ($5 / $30) for comparable tasks. V4 Flash drops the floor further to $0.14 / $0.28 per 1M with the same 1M context window. The 98% cache-hit discount on both makes V4 the dominant choice for high-volume RAG and classification workloads where prompts are cache-friendly. DeepSeek R2 (reasoning successor to R1) remains delayed per reports about Huawei Ascend training challenges.

Moonshot Kimi Family - May 2026 NEW​

ModelParametersContextNotes
Kimi K32.8T total / 104B active (MoE)1MJuly 16, 2026 NEW (open weights July 27). Largest open-weight model to date. Always-on thinking, multimodal. $3 / $15 per 1M ($0.30 cached input). Artificial Analysis Intelligence Index 57.1, third overall at launch behind Fable 5 and GPT-5.6 Sol; first open model to top WebDev Arena. Moonshot's flagship, superseding K2.7 Code.
Kimi K2.61T total / 32B active (MoE)-Released April 20, 2026. Modified MIT license. Native video input; Agent Swarm scaling to 300 sub-agents and 4,000 coordinated steps. Ties GPT-5.5 on SWE-Bench Pro (58.6%); SWE-bench Verified ~80.2%.
Kimi K2.7 Code1T total / 32B active (MoE)256KJune 12, 2026 NEW. Coding-focused build on K2.6 (Modified MIT) with a MoonViT vision encoder. Reports about +21.8% over K2.6 on Moonshot's own Kimi Code Bench v2 with roughly 30% fewer thinking tokens (vendor benchmark). API about $0.95 / $4.00 per 1M.
Kimi K2-Thinking-0905--First model to hit 100% on AIME 2025 (reasoning variant).

Best for: Long-horizon agent workloads, video understanding, open-weight agent stack alternative to closed frontier.

Alibaba Qwen 3.x Family - May 2026 NEW​

ModelParametersLicenseNotes
Qwen3.8-Max2.4T total / 95B active MoEQwen3.8-Max License (gated)August 12, 2026. 262K context native, extensible to ~1,010,000. Open weights under a bespoke license, not Apache: attribution required above 100M MAU or $20M monthly revenue, and a separate paid license is required for Model-as-a-Service or AI-assistant businesses above $50M aggregate revenue. The open checkpoint is text-input-only; the API version is multimodal.
Qwen3.8-27B27B denseApache 2.0August 14, 2026. The more permissive and more modality-complete artifact: accepts image and video input where the open Max checkpoint does not. 262K context, extensible to ~1M. Dense rather than MoE, which makes it the practical single-GPU option.
Qwen 3.6 Max-Preview~1T MoECommercial previewReleased ~April 20–27, 2026. 262K context. Tops six coding benchmarks per Alibaba.
Qwen 3.6-Plus--Released April 2, 2026. Enhanced coding.
Qwen 3.6-35B-A3B35B / 3B active MoEApache 2.0Released April 16, 2026. Open-weight workhorse.
Qwen2.5-Coder-32B32BApache 2.0Previous-generation open coding leader.
Qwen2.5-72B72BApache 2.0Previous-generation multilingual leader.
Qwen2.5-7B7BApache 2.0Efficient self-hosted option.

Mistral Family​

ModelParametersContextNotes
Mistral Medium 3.5128B dense256KMay 2026 NEW. Released April 29, 2026. Merges Magistral (reasoning) + Pixtral (vision) + Devstral 2 (coding) into one model. 77.6% on SWE-Bench Verified. $1.50/M input tokens.
Voxtral TTS4B open-weightsstreamingMay 2026 NEW (March 23 release, CC BY-NC 4.0). 70ms latency, 9 languages, 3-second voice cloning.
Mistral Large 3675B (MoE, 41B active)256KSparse MoE; parity with best open-weight models; #2 OSS non-reasoning on LMArena.
Mistral Small 4-256KHybrid instruct/reasoning/coding; released March 2026.
Mistral 3 (14B/8B/3B)3B–14B-Unified family: multilingual, multimodal, Apache 2.0.
Mixtral 8x22B141B (MoE)-Previous gen; still viable for throughput.

Google Gemma Family - May 2026 NEW​

ModelParametersContextLicenseNotes
Gemma 4 (31B dense)31B256KApache 2.0Released April 2, 2026. 140+ languages; native vision/audio; function calling.
Gemma 4 (26B-A4B MoE)26B / 4B active256KApache 2.0Sparse MoE variant.
Gemma 4 E4B8B256KApache 2.0Edge-suitable.
Gemma 4 E2B5.1B / 2.3B active256KApache 2.0Smallest variant; mobile/embedded.
DiffusionGemma (26B-A4B MoE)26B / ~4B active256KApache 2.0June 10, 2026 NEW. Google DeepMind's first open-weight text-diffusion model; denoises blocks of tokens in parallel for roughly 4x faster generation (1000+ tokens/sec on one H100). Lower quality than standard Gemma 4; aimed at low-latency and in-line editing.

Zhipu / Z.ai GLM Family - June 2026 NEW​

ModelParametersContextLicenseNotes
GLM-5.3Post-trained on the same 744B / 40B-active base as GLM-5.21MWeights withheld at launchAugust 14, 2026 via the GLM Coding Plan. The entire gain comes from extended post-training rather than a new pretraining run, a useful datapoint on where capability now comes from. Z.ai says cyber capability grew faster than anticipated as post-training scaled, claims a CyberGym lead, and staged the open-weight release pending safety evaluation, targeting roughly two weeks out (around August 28, 2026).
GLM-5.2744B total / 40B active (MoE)1MMITCoding-plan access June 13, 2026; open weights June 16-17. Built for long-horizon agentic coding and tool use. Reports SWE-Bench Pro 62.1 (ahead of GPT-5.5 at 58.6 on that benchmark) and a long-horizon coding score near the closed frontier; figures are vendor-reported. API roughly $1.40 / $4.40 per 1M; weights on Hugging Face.

Best for: Open-weight agentic coding and long-horizon tool use where a 1M context and a permissive license matter. Verify benchmark claims on independent leaderboards.

Thinking Machines Inkling - July 2026 NEW​

ModelParametersContextLicenseNotes
Inkling975B total / 41B active (MoE)1M (64K or 256K via the lab's Tinker API)Open weightsReleased July 15, 2026: Thinking Machines Lab's first public model, pretrained on 45T tokens of text, image, audio, and video. SWE-Bench Verified 77.6%; the leading US open-weights model per Artificial Analysis, with safety scores the lab reports as aligning with frontier models. NVFP4 checkpoint optimized for NVIDIA Blackwell.
Inkling-Small (preview)276B total / 12B active-Open weightsAnnounced alongside Inkling for lower cost and latency.

Why it matters: A brand-new US lab shipping the leading American open-weights model, positioned explicitly as a fine-tuning foundation. Until July the open frontier was dominated by Chinese labs; Kimi K3 and Inkling landing in the same week is the strongest open-weights month on record.

Meta Muse Spark (Closed Weights) - May 2026 STRATEGIC SHIFT​

AttributeValue
LicenseClosed weights - first proprietary model from Meta Superintelligence Labs
CapabilitiesMultimodal reasoning with Instant / Thinking / Contemplating modes
ReleasedApril 8, 2026

Strategic significance: Meta's first non-open model since the original Llama era. Signals that frontier-quality work may require a closed-development feedback loop. Llama 4 Behemoth release was simultaneously paused through fall 2026 amid capability concerns. The open-vs-closed equilibrium is now two-tier: frontier closed lags 6–12 months ahead; open weights catch up via distillation, RL, and ecosystem iteration.

July 2026 update: Muse Spark 1.1 shipped July 9 alongside the public preview of the Meta Model API, Meta's first self-serve paid API: OpenAI-compatible, $1.25 / $4.25 per 1M, roughly a quarter of rival flagship rates. Vendor-reported benchmarks lead on scaled tool use (MCP Atlas 88.1) and professional tool use (JobBench 54.7). Meta charging for API access completes the pivot away from open-weight Llama; there is no Llama 5, and Behemoth remains shelved.

August 2026 update: Muse Glimmer (August 10) is Meta's first open-weight release since Llama 4 and, at Apache 2.0, its most permissive license ever for an open model. It is a 30B dense multimodal model aimed at always-on local agent work (local coding agents, function calling, LLM-as-a-judge), with a 131,072-token context; quantized to 4-bit it fits under 20GB and runs on a single 24GB consumer GPU. Muse Spark 1.2 and Muse Code, a terminal coding agent, shipped alongside it, notable for a muse-spark-1.2-contributor tier priced at $0.10 / $0.20 per 1M (against $1.25 / $4.25 standard) in exchange for permission to train on your prompts and completions. Data-for-discount as an explicit, published API tier is new, and worth a policy decision before anyone enables it.


The August 2026 Open-Weight Licensing Split​

August was the month open weights stopped meaning one thing. Three postures now coexist, and the license is as much a design input as the benchmark:

ModelReleasedSizeLicense postureWhat the license actually does
Qwen3.8-Max (Alibaba)Aug 122.4T / 95B activeBespoke, commercially gatedFree use, modification, and resale, but attribution is required above 100M MAU or $20M monthly revenue, and a separate paid license is required to run a Model-as-a-Service or AI-assistant business above $50M aggregate revenue
Qwen3.8-27B (Alibaba)Aug 1427B denseApache 2.0No conditions. The smaller sibling is both more permissive and more modality-complete than the flagship
Muse Glimmer (Meta)Aug 1030B denseApache 2.0No conditions; Meta's most permissive open license to date
Tencent Hy3Global Aug 5 (model Jul 6)295B / 21B activeApache 2.0Fully permissive with no geographic carve-outs, reversing the April preview's restrictive license that excluded the EU, UK, and South Korea
Ling-3.0-flash / tiny (Ant Group)Aug 5 / Aug 11124B / 5.1B active; 7.9B / 1.3B activeMITNo conditions
Nemotron 3.5 Lightning (NVIDIA)Aug 1130B / 3B activeOpenMDW-1.1Linux Foundation license, free for commercial use
GLM-5.3 (Z.ai)Aug 14744B baseWeights withheldOpen release deliberately staged pending safety evaluation after cyber capability grew faster than expected; Z.ai gave a target of roughly two weeks (around August 28, 2026)

Two things follow for anyone building on open weights. First, read the license before the model card: a gated license can make a "open" flagship unusable for exactly the SaaS business you were planning, while its smaller sibling is unencumbered. Second, withholding is now a legitimate outcome: a lab can ship a model commercially and hold the weights on safety grounds. Z.ai did publish a target date, so treat it as a dated plan rather than an open-ended promise, and do not build a roadmap on weights that have not shipped.

Small and On-Device Models - August 2026​

ModelSizeContextLicenseNotes
Ling-3.0-tiny (Ant Group)7.9B / 1.3B active256KMITGenuinely laptop-class agentic model: roughly 8.3 GiB peak memory at 8K context, 86-90 tok/s on an M4 Pro MacBook at FP8
LFM2.5-2.6B (Liquid AI)2.6B128KOpen weightsBuilt for on-device tool calling and multi-step planning rather than chat; under 2.5 GB memory, runs down to a Raspberry Pi
LFM2.5-VL-3B (Liquid AI)3B-Open weightsOn-device vision-language model for screen understanding and GUI grounding (August 12)
Shieldstral 1.0 (Mistral)3B32KApache 2.0Policy-adaptive multimodal safety classifier (text and image, 12 languages): moderation policies are supplied in natural language at inference time, so a policy change needs no retraining. Runs on one 16GB GPU
Muse Glimmer (Meta)30B dense131KApache 2.0Under 20GB at 4-bit; targets always-on local agents

The pattern worth noting: the small-model tier stopped competing on chat quality and started competing on tool calling, planning, and screen grounding, which are the capabilities a local agent actually needs.


Specialized Models​

Coding Mastery (June 2026)​

ModelSpecializationWhy it wins
Claude Fable 5Capability ceilingMythos-class coding now generally available; highest frontier score on Cognition's FrontierCode and SOTA on CursorBench per Anthropic; 2x Opus 4.8 price
GPT-5.5Single-shot coding leader (published)SWE-bench Verified 88.7%; Terminal-Bench 2.1 78.2%
Claude Opus 4.8Long-running agentic codingSWE-bench Verified 88.6%; SWE-Bench Pro 69.2%; Dynamic Workflows with parallel subagents in Claude Code
Claude Opus 4.7Predecessor flagship codingSWE-bench Verified 87.6%; SWE-Bench Pro 64.3%
Claude Sonnet 4.6Workhorse codingPowers Claude Code at lower cost; 1M context
Llama 4 MaverickOpen-source codingOpen weights; competitive on coding benchmarks
Qwen 3.6 Coder / Qwen2.5-Coder-32BSelf-hosted codingBest price-to-performance for self-hosted IDEs
DeepSeek V4 Pro / R1-Distill-70BOpen reasoning + codeBest open reasoning at 70B; V4 Pro is open-weight 1.6T/49B-active MoE
Z.ai GLM-5.2Open agentic codingJune 2026; 744B / 40B-active MoE, 1M context, MIT; reports SWE-Bench Pro 62.1 ahead of GPT-5.5 on that benchmark (vendor-reported); about $1.40 / $4.40 per 1M
Kimi K2.7 CodeOpen long-horizon codingJune 2026; 1T / 32B-active MoE, Modified MIT; tuned from K2.6 for software work with fewer thinking tokens
Cohere North Mini Code 1.0Open lightweight codingJune 2026; 30B / 3B-active MoE on a single H100, Apache 2.0; Cohere's first open coding model

Reasoning & Math​

ModelApproachBest For
Claude Fable 5Always-on adaptive thinking at the Mythos capability tierThe hardest reasoning problems where ceiling beats cost
Claude Opus 4.8 (thinking)Adaptive thinking with parallel subagentsSoftware planning, codebase-scale work, agentic reasoning
GPT-5.5 reasoningMaximum-compute reasoningCompetition math (AIME 2025 81.2% on Instant), ARC-AGI-2 85.0% leader
Gemini 3.1 Pro Deep ThinkSustained chain-of-thoughtScientific reasoning, GPQA Diamond leader
DeepSeek-R1RL-based thinkingOpen-source logical inference, competitive math
Grok 4.3 (DeepSearch)Web-grounded reasoningResearch tasks needing live information

Long Context (1M+)​

ModelWindowRecall Performance
Llama 4 Scout10MIndustry-leading open-weight context window
Gemini 3.1 Pro / Flash1MBest quality at 1M context; proven at scale
Claude Fable 51MAnthropic reports improved long-context performance with persistent memory across long sessions
Claude Opus 4.8 / 4.7 / Sonnet 4.61MFull 1M at standard pricing; reliable recall
Llama 4 Maverick1MOpen-weight 1M context with MoE efficiency

Embedding Models​

API Embedding Models (May 2026)​

ModelDimensionsMax TokensMTEB ScoreCost/1M
OpenAI text-embedding-3-large3072819164.6$0.13
OpenAI text-embedding-3-small1536819162.3$0.02
Voyage-310243200067.8$0.06
Cohere embed-v3102451266.4$0.10
Google text-embedding-004768204866.1$0.025

Open Source Embedding Models​

ModelDimensionsMax TokensMTEBNotes
BGE-large-en-v1.5102451263.9Instruction-tuned
E5-mistral-7b-instruct40963276866.6Strong with instructions
Nomic-embed-text-v1.5768819262.3Long context, open
GTE-Qwen2-7B358432K72.1State-of-the-art open embedding

Embedding Selection Guide​

RequirementRecommendedWhy
Best qualityVoyage-3 or text-embedding-3-largeHighest MTEB
Cost-efficienttext-embedding-3-small$0.02/1M
Self-hostedGTE-Qwen2-7BBest open MTEB
Long documentsNomic or Voyage-38K+ context
MultilingualCohere embed-v3Built for multilingual

Model Selection Framework​

Decision Tree​

What is your primary constraint?

├── Cost → Use smaller model, consider open source
│ ├── Very cost sensitive → DeepSeek V4 Flash, GPT-5.5-mini, Claude Haiku 4.5, Gemini 3.1 Flash
│ └── Moderate budget → Claude Sonnet 4.6, GPT-5.5 Instant, DeepSeek V4 Pro
│
├── Quality + Reasoning → Use frontier models
│ ├── Highest reasoning → Claude Fable 5, Claude Opus 4.8 (thinking), GPT-5.5 reasoning, Gemini 3.1 Pro Deep Think
│ └── Coding + reasoning → Claude Opus 4.8 with Dynamic Workflows, Claude Sonnet 4.6 (Extended Thinking), GPT-5.5
│
├── Latency → Use fast models
│ ├── <100ms response → Gemini 3.1 Flash, GPT-5.5-mini
│ └── <500ms response → Claude Haiku 4.5, Claude Opus 4.8 fast mode, Grok 4.1 Fast
│
├── Self-hosting → Use open models
│ ├── Maximum capability → Llama 4 Maverick, DeepSeek-V3
│ ├── Good balance → Llama 4 Scout, Llama 3.3 70B, Qwen2.5-72B
│ └── Edge/mobile → Mistral 3 3B, Phi-4
│
└── Privacy → Self-host or use on-prem
└── Choose open models with appropriate license

Semantic Routing​

Static decision trees are being replaced by Semantic Routers:

  • How it works: A small, fast embedding model vectorises the query. If it matches a "known easy" cluster, route to a cheap model (Gemini 3.1 Flash, DeepSeek V4 Flash, Claude Haiku 4.5). If it hits an "agentic/logic" cluster, route to Claude Opus 4.8 or GPT-5.5 with reasoning.
  • Benefit: Automates cost-optimization without hardcoded rules.
  • Implementation: Tools like semantic-router (Python) or custom Weaviate/Pinecone classifiers.

Sovereign AI and Data Residency​

The 2026 Regulatory Reality: Enterprises must comply with GDPR (EU), DPDPA (India), Saudi Arabia PDPL, and sectoral rules. "Sovereign AI" is now a product category.

SolutionProviderUse Case
Azure Government/SovereignMicrosoftDedicated infra in 40+ regions; approved for US Gov/EU NIS2
AWS Sovereign CloudAmazonPhysically isolated VPCs; GDPR-safe EU regions
Google Distributed CloudGoogleAir-gapped on-prem Gemini deployment
Private Llama 4 / 3.3Meta (self-host)Maximum data sovereignty; open weights (Llama 4 MoE or 3.3 dense)
DeepSeek (self-host)DeepSeek (open)Open weights; no data leaves your infra
Mistral Large 3 (self-host)Mistral (Apache 2.0)675B MoE; open weights; strong multilingual

Tradeoff: Sovereign clouds carry a 20-30% premium over standard global regions but are mandatory for finance and government.

Cost Comparison at Scale (May 2026)​

Assume 1M requests/day, 1K input + 500 output tokens:

ModelInput Cost/DayOutput Cost/DayTotal/Month
Claude Sonnet 4.6$3,000$7,500$315,000
GPT-5.4$2,500$7,500$300,000
Gemini 3.1 Pro$2,000$6,000$240,000
GPT-5.4-mini$750$2,250$90,000
Gemini 3.1 Flash$100$1,500$48,000
Self-hosted Llama 4 Scout*--~$15,000
Self-hosted Llama 3.3 70B*--~$50,000

*Self-hosted Llama 4 Scout fits on a single H100; Llama 3.3 70B assumes 4x H100 GPUs


Capability Comparison​

Benchmark Performance (May 2026)​

ModelMMLUHumanEvalSWE-bench VerifiedNotes
Claude Opus 4.6---Top-tier across reasoning and coding; specific scores check latest
GPT-5.4---33% fewer factual errors vs GPT-5.2; strong coding + agentic
Claude Sonnet 4.6---Approaches Opus-level on many tasks
Gemini 3.1 Pro---State-of-the-art Google reasoning
Grok 4---Competitive reasoning; real-time web integration
Llama 4 Maverick---Beats GPT-4o, Gemini 2.0 Flash on reported benchmarks
DeepSeek-R190.892.649.2%First open-source reasoning model; math/code strong

Source: Respective technical reports and LMSYS Chatbot Arena / LMArena, April 2026. Benchmark scores for newest models (Opus 4.6, GPT-5.4, Gemini 3.1) are evolving rapidly -- always verify with current leaderboards.

Task-Specific Recommendations (May 2026)​

TaskRecommended ModelsWhy
Autonomous Coding AgentClaude Sonnet 4.6 / Opus 4.6Powers Claude Code; 1M context; top tool reliability
Complex ReasoningGPT-5.4 Pro, Claude Opus 4.6 (thinking), DeepSeek-R1Maximum reasoning power
Agentic Computer UseGPT-5.4First general-purpose model with native computer-use capabilities
High-Volume APIGemini 3.1 Flash, GPT-5.4-miniLowest cost per token in class
Long Context RAGGemini 3.1 Pro/Flash (1M), Claude Sonnet 4.6 (1M)Verified long-range recall
Ultra-Long ContextLlama 4 Scout (10M)Industry-leading 10M context; open weights
Multimodal Real-timeGemini 3.1 FlashReal-time audio/video/text native
Private ProductionLlama 4 Maverick, Llama 3.3 70B, Qwen2.5-72BHigh capability with local control
Open-source CodingLlama 4 Maverick, Qwen2.5-Coder-32BOpen weights, strong coding benchmarks
Creative/ChatGPT-5.4Strong conversation quality and instruction following

Interview Questions​

Q: How would you select a model for a production RAG system?​

Strong answer: I evaluate across these dimensions:

1. Quality requirements:

  • Test on representative queries from the actual domain
  • Measure answer correctness, hallucination rate, citation accuracy

2. Cost analysis:

Monthly cost = requests/day × 30 × avg_tokens × rate

Always calculate for top 2-3 candidates.

3. Latency requirements:

  • If <200ms TTFT needed: Gemini 3.1 Flash, Claude Haiku 4.5, GPT-5.4-mini
  • If quality is paramount: Accept 2-3s with Claude Opus 4.6 or GPT-5.4

4. Operational requirements:

  • Self-hosting: Llama 4 Scout/Maverick, DeepSeek-V3
  • Compliance / data residency: Azure Sovereign or self-hosted

5. Practical selection:

  • Start with Claude Sonnet 4.6 or GPT-5.4 for prototyping
  • A/B test Gemini 3.1 Flash for 80% of queries (cost)
  • Keep frontier on hard queries via semantic routing

Q: Explain the tradeoffs between proprietary and open source models.​

Strong answer:

FactorProprietary (OpenAI, Anthropic)Open Source (Llama, DeepSeek)
QualityGenerally higher (slightly)Catching up rapidly
CostPer-token pricingCompute + ops
ControlLimitedFull
PrivacyData goes to providerStays on-prem
UpdatesAutomaticManual
CustomizationLimited fine-tuningFull fine-tuning
Ops overheadNoneSignificant

Key insight (2026): DeepSeek-V3/R1 and now Llama 4 have changed this conversation -- open models match or beat GPT-4o on many benchmarks. With Llama 4 Maverick matching DeepSeek V3 on reasoning at half the active parameters, the gap is narrower than ever.

Q: What is the difference between GPT-5.4 Pro and Claude Opus 4.6's Extended Thinking?​

Strong answer: Both use internal chain-of-thought, but the mechanics differ:

  • GPT-5.4 Pro: OpenAI's maximum-compute reasoning tier ($30/$180 per 1M tokens). Allocates high compute to reasoning. Internal thoughts are not exposed. Successor to the o3 line.
  • Claude Opus 4.6 Adaptive Thinking: Returns thinking tokens in a separate <thinking> block. Configurable budget_tokens. You can inspect the reasoning chain for debugging. Full 1M context with 128K max output.

Production choice: For debugging and trust-building, Claude's visible thinking is more transparent. For maximum raw reasoning power on math/competition tasks, GPT-5.4 Pro leads. For cost-effective reasoning, Claude Sonnet 4.6 or GPT-5.4-mini are strong choices.


References​


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