Kimi K2 Thinking
API ID: moonshotai/kimi-k2-thinking-20251106
About Kimi K2 Thinking
Kimi K2 Thinking is Moonshot AI’s most advanced open reasoning model to date, extending the K2 series into agentic, long-horizon reasoning. Built on the trillion-parameter Mixture-of-Experts (MoE) architecture introduced in Kimi K2, it activates 32 billion parameters per forward pass and supports 256 k-token context windows. The model is optimized for persistent step-by-step thought, dynamic tool invocation, and complex reasoning workflows that span hundreds of turns. It interleaves step-by-step reasoning with tool use, enabling autonomous research, coding, and writing that can persist for hundreds of sequential actions without drift. It sets new open-source benchmarks on HLE, BrowseComp, SWE-Multilingual, and LiveCodeBench, while maintaining stable multi-agent behavior through 200–300 tool calls. Built on a large-scale MoE architecture with MuonClip optimization, it combines strong reasoning depth with high inference efficiency for demanding agentic and analytical tasks.
Model Specifications
Best For
- Complex reasoning, math problems, multi-step logic
- Conversations, content writing, general assistance
Consider Alternatives For
- Image understanding (needs vision capability)
- Simple Q&A (cheaper models available)
💰 Real-World Cost Examples
Estimated monthly costs for common use cases
Moonshot AI Model Lineup
Compare all models from Moonshot AI to find the best fit
| Model | Input | Output | Context | Capabilities |
|---|---|---|---|---|
| Kimi K2 Thinking Current | $0.40 | $1.75 | 262k | chat reasoning tool_use |
| Moonlight 16B A3B Instruct | Free | Free | 8k | chat |
| Moonlight 16B A3B Instruct | Free | Free | 8k | chat |
| Kimi K2 0711 | Free | Free | 131k | chat tool_use |
| Kimi Dev 72B | Free | Free | 131k | chat reasoning |
| Kimi VL A3B Thinking | Free | Free | 131k | chat vision reasoning |
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