Kimi K2 Thinking vs GPT-5.1
At a Glance
| Compare |  Kimi K2 ThinkingMoonshot AI |  GPT-5.1OpenAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | UnrankedNot in the 46-model eligible cohort | #37 of 4625.7 score · 2/3 sources · provisional · missing LiveBench · full-core range 17.1–50.5 |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $0.60Openrouter ↗ · Sep 23, 2026 | $1.25Openai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $2.50Openrouter ↗ · Sep 23, 2026 | $10.00Openai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 262K | 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 | Kimi-K2-Thinking | GPT-5.1 |
|---|---|---|
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 78.55100% of row best · points · Kimi K2 Thinking · 7,821 output tokens / case | 75.9897% of row best · points · GPT-5.1 · 3,970 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above | 0 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 | Kimi-K2-Thinking | GPT-5.1 |
|---|---|---|
| Developer | Moonshot AI | OpenAI |
| Family | Kimi K2 Thinking | Gpt 5 1 |
| Model | Kimi-K2-Thinking | GPT-5.1 |
| Version | Kimi-K2-Thinking | GPT-5.1 |
| Lifecycle | active | active |
| Released | 2025-11-06 | 2025-11-13 |
| Knowledge cutoff | Unknown | 2024-09-30 |
| Input modalities | Text | Text, Image |
| Output modalities | Text | Text |
| Context window | 262K | 400K |
| Total parameters | 1T | Unknown |
| Active parameters | 32B | Unknown |
| License | other | Unknown |
| Open weights | Yes | No |
| API available | Yes | Yes |
| Self-hostable | Yes | No |
| Provider access | Hugging Face (Standard), Openrouter (Standard) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
Kimi K2 Thinking Capabilities
GPT-5.1 Capabilities
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Primary Evidence
Sources and Freshness
Questions
Kimi K2 Thinking vs GPT-5.1 FAQs
Is Kimi K2 Thinking or GPT-5.1 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Kimi K2 Thinking and GPT-5.1, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Kimi K2 Thinking or GPT-5.1?+
Kimi K2 Thinking is $0.60 and GPT-5.1 is $1.25 per million tokens, so Kimi K2 Thinking is cheaper on this metric. Kimi K2 Thinking is $2.50 and GPT-5.1 is $10.00 per million tokens, so Kimi K2 Thinking is cheaper on this metric.
Which has a larger context window, Kimi K2 Thinking or GPT-5.1?+
GPT-5.1 has the larger sourced context window. Kimi K2 Thinking supports 262K and GPT-5.1 supports 400K.
Which performs better in benchmarks, Kimi K2 Thinking or GPT-5.1?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Kimi K2 Thinking or GPT-5.1 be self-hosted?+
Kimi K2 Thinking is the only model in this pair currently marked as self-hostable. Kimi K2 Thinking is open weight; GPT-5.1 is not marked open weight.
Can Kimi K2 Thinking and GPT-5.1 understand images?+
Kimi K2 Thinking is not 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, Kimi K2 Thinking or GPT-5.1?+
Kimi K2 Thinking has the larger sourced maximum output: Kimi K2 Thinking supports 131K and GPT-5.1 supports 128K output tokens.
Do Kimi K2 Thinking and GPT-5.1 support reasoning and tool use?+
Kimi K2 Thinking: reasoning and tool calling. GPT-5.1: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Kimi K2 Thinking or GPT-5.1?+
Kimi K2 Thinking has 2 sourced provider routes; GPT-5.1 has 2, a tie.
Which offers better value, Kimi K2 Thinking 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.