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    Kimi K2 Thinking · kimi-k2-thinking

    Moonshot · 6 Nov 2025

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    benchmarks

    Kimi K2 Thinking is Moonshot's open-weight, text-only reasoning model, designed for coding, complex problem solving and tool-assisted workflows with a 256K-token context window. Its published benchmark results include tool-assisted evaluations, which should not be interpreted as unaided model performance.

    context: 256Ktext$0.60 / $2.50 per 1M tokens (in / out)

    Benchmark results

    Every figure links to where it was published. Compare like with like — harnesses and prompt setups differ between vendors.

    BenchmarkScoreSource
    AIMECompetition mathematics99.1%Nov 2025View
    GPQA DiamondPhD-level science questions84.5%Nov 2025View
    Humanity's Last Exam — with tools44.9%Nov 2025View
    Humanity's Last Exam — without tools26.9%Nov 2025View
    LiveCodeBenchFresh competitive-programming problems83.1%Nov 2025View
    SWE-bench VerifiedResolving real GitHub issues71.3%Nov 2025View
    Terminal-BenchLong-horizon command-line agent tasks35.7%6 Nov 2025View
    FrontierMath21.4%5 Dec 2025View

    Weighted mean of 8 verified benchmark results: AIME 99.1%, GPQA Diamond 84.5%, Humanity's Last Exam — with tools 44.9%, Humanity's Last Exam — without tools 26.9%, LiveCodeBench 83.1%, SWE-bench Verified 71.3%, Terminal-Bench 35.7%, FrontierMath 21.4%.

    Capabilities

    • Extended reasoning for mathematical, scientific and analytical text tasks.
    • Code generation and repository-level software engineering with appropriate tools.
    • Interleaved reasoning and tool calling across long agent workflows.
    • Processing long documents and code within a documented 256K-token context window.
    • Open-weight deployment with a published INT4 quantized format.

    What improved

    • Introduces a dedicated thinking model alongside the earlier Kimi K2 instruction-following models.
    • Expands context from the original K2 release's 128K tokens to 256K tokens; this is not an increase over every intervening K2 variant.
    • Emphasizes sustained reasoning interleaved with long sequences of tool calls.
    • Uses quantization-aware training for the published INT4 deployment format.

    Known flaws & limitations

    • Text-only inputs do not provide native image, audio or video understanding.
    • The trillion-parameter mixture-of-experts architecture requires substantial memory and serving infrastructure despite sparse activation and quantization.
    • Extended reasoning and repeated tool calls can increase latency and total token expenditure.
    • Tool-assisted benchmark results depend on external tools, evaluation scaffolding and execution budgets.
    • Strong benchmark performance does not guarantee factual accuracy or successful completion of unfamiliar tasks.

    Risks, safety & security issues

    • Agent deployments with excessive tool permissions can expose files, credentials and external services; use least-privilege access.
    • Untrusted documents and tool outputs can introduce prompt-injection instructions; isolate them from privileged actions.
    • Generated code and shell commands can be unsafe or incorrect; require sandboxing and review before execution.
    • Sensitive information included in prompts or tool results can propagate into logs or downstream services; minimize and redact sensitive data.

    Good fit for

    • Complex text-based reasoning where additional inference time is acceptable.
    • Coding and repository maintenance with tests, sandboxed execution and human review.
    • Long-document analysis and synthesis.
    • Tool-assisted research and multi-step workflows with tightly scoped permissions.

    Poor fit for

    • Native image, audio or video understanding.
    • Latency-critical applications that require consistently short responses.
    • Small-device or low-memory self-hosting.
    • Unsupervised consequential decisions or unrestricted access to production systems.

    Profile last reviewed 10/20/2026 and re-checked automatically every few hours against the vendor's published documentation, papers and public leaderboards. Scores come from the cited benchmark results above — confirm limits and pricing against the provider's own documentation before building on them.