Claude Sonnet 5 vs GPT-5.1
At a Glance
| Compare | Claude Sonnet 5Anthropic |  GPT-5.1OpenAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #26 of 4660.1 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 40.0–73.4 | #37 of 4625.7 score · 2/3 sources · provisional · missing LiveBench · full-core range 17.1–50.5 |
| CostLower is better · Published-token output estimate | #29 of 44$0.194 per LiveBench case | UnrankedNot in the 44-model eligible cohort |
| EfficiencyHigher is better · MM Efficiency v1.5 | #30 of 3847.4 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 37.4–54.0 | UnrankedNot in the 38-model eligible cohort |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $2.00Anthropic ↗ · Sep 3, 2026 | $1.25Openai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $10.00Anthropic ↗ · Sep 3, 2026 | $10.00Openai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,000K | 400K |
| Model facts checked | Aug 28, 2026View model evidence → | Sep 3, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | Claude Sonnet 5 | GPT-5.1 |
|---|---|---|
| LMArena Document Arenadocument-2026-09-13-d25aabda0010 · arena_rating · leader | 1,466.14100% of row best · rating · claude-sonnet-5-high; 95% CI [1458.49407458, 1473.77896309]; votes 7411; rank 17 | 1,403.1796% of row best · rating · gpt-5.1; 95% CI [1393.82886201, 1412.50542979]; votes 8244; rank 42 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader | 1,442.15100% of row best · rating · claude-sonnet-5-high; 95% CI [1437.57467941, 1446.71829948]; votes 35301; rank 62 | 1,422.5799% of row best · rating · gpt-5.1; 95% CI [1418.95842118, 1426.18777801]; votes 42982; rank 100 |
| LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · leader | 1,277.16100% of row best · rating · claude-sonnet-5-high; 95% CI [1269.57643110, 1284.74576666]; votes 10289; rank 32 | 1,235.0897% of row best · rating · gpt-5.1; 95% CI [1227.35514387, 1242.80648733]; votes 10205; rank 65 |
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 86.51100% of row best · points · Claude Sonnet 5 (max effort) · 71,003 output tokens / case | 75.9888% of row best · points · GPT-5.1 · 3,970 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above | 3 benchmark winsNo overall winner | 0 benchmark winsNo overall winner |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Side-by-Side Facts
| Field | Claude Sonnet 5 | GPT-5.1 |
|---|---|---|
| Developer | Anthropic | OpenAI |
| Family | Claude 5 | Gpt 5 1 |
| Model | Claude Sonnet 5 | GPT-5.1 |
| Version | Claude Sonnet 5 | GPT-5.1 |
| Lifecycle | active | active |
| Released | 2026-06-30 | 2025-11-13 |
| Knowledge cutoff | Unknown | 2024-09-30 |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,000K | 400K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Anthropic (Standard), Deepinfra (Standard), Openrouter (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
Claude Sonnet 5 Capabilities
GPT-5.1 Capabilities
Related Comparisons
All image comparisons →| A | Pair | B | Context |
|---|---|---|---|
Claude Sonnet 4.6Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Sonnet 5Anthropic | vs | GPT-6 AstraOpenAI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Sonnet 5Anthropic | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Sonnet 5Anthropic | vs |  DeepSeek-V4.1-FlashDeepSeek | cross-developer peersimage, text |
Claude Sonnet 5Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Sonnet 5Anthropic | vs |  Qwen3.8-MaxQwen | cross-developer peersimage, text |
Claude Sonnet 5Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
 MiniMax-M3MiniMax | vs | Claude Sonnet 5Anthropic | cross-developer peersimage, text |
Claude Sonnet 5Anthropic | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Claude Sonnet 5Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Sonnet 5Anthropic | vs | Seed 2.1 ProByteDance Seed | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Sonnet 5 vs GPT-5.1 FAQs
Is Claude Sonnet 5 or GPT-5.1 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Sonnet 5 and GPT-5.1, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Sonnet 5 or GPT-5.1?+
Claude Sonnet 5 is $2.00 and GPT-5.1 is $1.25 per million tokens, so GPT-5.1 is cheaper on this metric. Claude Sonnet 5 is $10.00 and GPT-5.1 is $10.00 per million tokens, so they are tied on this metric.
Which has a larger context window, Claude Sonnet 5 or GPT-5.1?+
Claude Sonnet 5 has the larger sourced context window. Claude Sonnet 5 supports 1,000K and GPT-5.1 supports 400K.
Which performs better in benchmarks, Claude Sonnet 5 or GPT-5.1?+
There is no overall benchmark winner: An overall winner requires at least two decisive benchmarks from at least two original publishers.
Can Claude Sonnet 5 or GPT-5.1 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Sonnet 5 is not marked open weight; GPT-5.1 is not marked open weight.
Can Claude Sonnet 5 and GPT-5.1 understand images?+
Claude Sonnet 5 is documented with image input; GPT-5.1 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Sonnet 5 or GPT-5.1?+
Neither has a larger sourced maximum output. Claude Sonnet 5 is 128K and GPT-5.1 is 128K.
Do Claude Sonnet 5 and GPT-5.1 support reasoning and tool use?+
Claude Sonnet 5: reasoning, tool calling, and image input. GPT-5.1: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Sonnet 5 or GPT-5.1?+
Claude Sonnet 5 has 3 sourced provider routes; GPT-5.1 has 2, so Claude Sonnet 5 has broader tracked availability.
Which offers better value, Claude Sonnet 5 or GPT-5.1?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.