Open-weight 2.8T reasoning model with a 1M-token window and vision input for long-horizon coding agents.
Output Speed *
Intelligence Index *
Context Window *
Input price
Output price
Performance
Frontier-Class Intelligence at Open-Weight Scale, Traded Against Speed
Benchmarks
Independent Data: Strong Intelligence Score, Below-Median Speed
Output Speed
Intelligence Index
MMLU *
GPQA *
HLE *
LiveCodeBench *
Technical Specifications
What the model supports
Comparison
Kimi K3 (Max) or Kimi K2.7 Code for Coding Agents?
Both models come from Moonshot AI and target agentic coding, so K2.7 Code is the natural cheaper alternative for K3 users. <cite index="16-5">K3 has a 1,048,576-token window, against K2.7 Code's 262,144.</cite> <cite index="34-4">K3 supports reasoning_effort; K2.7 Code does not.</cite> <cite index="24-9">Artificial Analysis measures K2.7 Code at 52 tokens per second</cite>, faster than K3's low-40s. K2.7 Code also has much lower token prices. The decision is whether your task needs K3's extra reach.
Choose Kimi K3 (Max) when repositories or evidence sets exceed 262K tokens, when agents run long autonomous sessions, or when screenshots and test output are part of the loop. Choose Kimi K2.7 Code for routine implementation, debugging and tool loops where lower token cost and faster output matter more than the larger window. <cite index="16-9,16-10">Test K3 on tasks beyond 256K context, and otherwise compare completed-task quality before changing defaults.</cite>
Limitations & Trade-offs
Best-Fit Workloads
Where this model earns its place
Repository-scale coding agents
Moonshot positions K3 for long-horizon coding, and its 1,048,576-token window lets an agent hold large codebases, logs and test output in one session. Moonshot lists agent scenarios such as Kimi Code, Codex and Claude Code. It fits multi-file refactors and autonomous debugging. Preserve reasoning_content between turns, and expect slower responses than lighter coding models.
Vision-in-the-loop front-end development
OpenRouter's model description says K3 iterates against images, logs, tests and runtime feedback.Wikipedia reports it outperformed competitors on Arena.ai's front-end web development benchmark at launch. Use it where an agent must inspect screenshots of a rendered UI and revise code. The per-request cost and speed profile make it better for build-time generation than interactive previews.
Long-horizon research and knowledge work
Fireworks lists agentic deep research among K3's main uses, and Moonshot highlights end-to-end knowledge work such as research reports with interactive visualizations. With max-effort reasoning and long context, it suits multi-step investigations over large source sets. Latency is high, so run these as background jobs rather than live user requests.
Large-document and evidence analysis
Moonshot lists flat per-token pricing with no tiering by context length, and context caching is automatic for regular requests. That helps when many questions run against the same large corpus, contract set or log archive. Send the stable prefix first so cache hits apply. Skip it for short documents, where reasoning overhead outweighs the benefit.