Open weights
Kimi K3 is Moonshot AI's native multimodal agentic flagship, released on July 16, 2026. It is a 2.8T-parameter MoE model with about 104B activated parameters per token and a 1,048,576-token context window. The full model weights, inference code, and technical report became publicly available on July 27 UTC / July 28 China Standard Time through Hugging Face and GitHub.
Architecture
K3 has 93 layers: one dense layer, 69 Kimi Delta Attention layers, and 24 Gated MLA layers. Stable LatentMoE routes each token to 16 of 896 experts and includes two shared experts. The hidden size is 7168, with 96 attention heads and a roughly 160K vocabulary. Its MoonViT-V2 vision encoder has 401M parameters.
Quantization-aware training starts at SFT. Released weights use MXFP4 with MXFP8 activations. The Hugging Face repository contains 96 Safetensors weight shards and roughly 1.42 TiB of weight-related large files. Moonshot recommends vLLM, SGLang, and TokenSpeed for inference.
Capabilities and API
K3 targets long-horizon software engineering, knowledge work, reasoning, and visual tasks. It accepts text, image, and video inputs and produces text. Its API supports function and tool calling, strict JSON Schema output, Partial Mode, dynamically loaded tools, automatic context caching, and OpenAI/Anthropic-compatible interfaces.
Thinking is always enabled. reasoning_effort supports low, high, and max, with max as the default. Multi-turn and tool workflows must pass the complete prior assistant message back unchanged, including reasoning_content and tool_calls.
Official evaluations
The open-weight model card reports 45 benchmarks represented here as 50 structured rows, including five paired no-tool/tool-augmented results. All K3 results use max reasoning effort and temperature 1.0. Representative scores include GPQA Diamond 93.5, DeepSWE 67.5, Terminal-Bench 2.1 88.3, BrowseComp 91.2, MCPMark-Verified 94.5, OSWorld-Verified 84.8, and OmniDocBench 91.1.
Pricing and access
Per 1M tokens, China pricing is ¥2 cached input, ¥20 uncached input, and ¥100 output; international pricing is $0.30, $3, and $15 respectively. API access is unlocked after at least a $1 successful top-up, and account tier determines rate limits.
License
Code, weights, configurations, and documentation use the Kimi K3 License. It permits use, modification, distribution, sublicensing, sale, deployment, and fine-tuning, subject to notice and legal-compliance requirements. MaaS operators with more than $20M aggregate revenue in any consecutive 12 months must obtain a separate agreement before commercial use. Commercial products exceeding 100M monthly active users or $20M monthly revenue must prominently display “Kimi K3.” The license includes exceptions for internal use, official Moonshot products, and certified inference partners.
Operational limits
- API sampling settings temperature=1.0, top_p=0.95, n=1, presence_penalty=0, and frequency_penalty=0 are fixed.
- Vision input does not accept public image URLs; use base64 data or an uploaded
ms:// file. - Moonshot says its web-search tool is being updated and is not currently recommended for production.
- Open weights still require very large storage, accelerator memory, high-speed interconnects, and compatible serving software.
Official sources
Hugging Face weights and model card · GitHub code and technical report · official technical blog · API quickstart · official pricing