Kimi K2 Thinking

#40 in Reasoning Models

Moonshot AI · thinking · since 2025-11-06 · 8× · last seen Jun 30, 2026

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Momentum

Kimi K2 Thinking is an Open-Weight Reasoning model (Mixture-of-Experts, 1 billion total parameters, 32 billion active parameters) released by Moonshot AI on November 6, 2025. It is designed as a "Thinking Agent" that interleaves reasoning processes (Chain-of-Thought) end-to-end with tool use and can reason coherently across 200-300 consecutive Tool calls. The model leverages native INT4 Quantization (Quantization-Aware Training) for lossless Inference acceleration and offers a context window of 256K Token; it achieves state-of-the-art results among Open-Source models on Benchmarks such as Humanity's Last Exam and BrowseComp. It is accessible via kimi.com, the Moonshot API (platform.moonshot.ai), and as open weights on Hugging Face and GitHub.

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