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Moonshot AI · Kimi
No. 36
Kimi K2 Thinking
Deep-reasoning open variant of Kimi K2 for hard problems.
Field notes
- Context window
- 262Ktokens
- Max output
- 66Ktokens
- Input price
- $0.60/ 1M tokens
- Output price
- $2.50/ 1M tokens
- Cached input
- $0.15/ 1M tokens
- Modalities
- Text
- Knowledge cutoff
- Apr 2025
- Released
- Nov 2025
- Parameters
- 1000B
- License
- Modified MIT
- Approx. speed
- —
Overview
What this model is
Kimi K2 Thinking is Moonshot's dedicated reasoning checkpoint (1T MoE, 32B active, Modified MIT) that extends test-time thinking and tool use for hard math, logic, and research tasks. It posts strong reasoning scores and long tool-call chains, but is slower and from the earlier K2 generation than K2.6. A capable open reasoner rather than a frontier agentic coder.
Strengths
- Strong deep-reasoning and tool-use scores
- Long tool-call chains for research
- Open Modified MIT weights, INT4-efficient
- Competitive math (AIME) performance
Trade-offs
- Slow due to extended thinking
- Older K2 generation than K2.6
- Agentic-coding reliability below the frontier
- Text-only input
Best for
- Hard math and logic problems
- Tool-augmented research agents
- Reasoning-heavy analysis
- Self-hosted reasoning
Not ideal for
- Latency-sensitive workloads
- Long autonomous production coding
Capabilities
Capability profile
Normalized 0–100 scores, comparable across the whole catalog.
- Reasoning
- 84
- Coding
- 72
- Math
- 88
- Writing
- 76
- Knowledge
- 80
- Speed
- 45
- Agentic
- 68
- Vision
- 5
- Multilingual
- 76
- Long Context
- 80
Benchmarks
How it scores
Public benchmark results, with independent third-party results where available. Bars normalize percentages to 100 and Elo ratings to a 1500 ceiling.
BenchmarkResult
GPQA Diamondindependent
ReasoningIndependent aggregators
84.5%
AIME 2025
MathVendor-reported
94%