AI/TLDR

Kimi K2.5

Moonshot AI's trillion-parameter open-weight multimodal agent model

Overview

Kimi K2.5 is Moonshot AI's open-weight flagship model, released on January 27, 2026 as the multimodal successor in the company's Kimi K2 line. It is a Mixture-of-Experts model with 1 trillion total parameters but only 32 billion active per token, which keeps inference cost low relative to its size. Unlike the original text-only Kimi K2, K2.5 is natively multimodal: it was built by continued pretraining over roughly 15 trillion mixed visual and text tokens and pairs the language backbone with a 400M-parameter MoonViT vision encoder.

K2.5 accepts text, images, and (experimentally) video, with a 256K-token context window. Moonshot positions it as a 'visual agentic' model aimed at real work, exposing four operating modes: Instant for quick answers, Thinking for step-by-step reasoning, Agent for research and content creation, and an Agent Swarm mode that can coordinate up to 100 sub-agents across many parallel steps for large-scale research, long-form writing, and batch tasks.

The weights are published on Hugging Face under a Modified MIT License that permits commercial use, so K2.5 can be self-hosted. It is also served through Moonshot's own Kimi API platform and through third parties including Amazon Bedrock and OpenRouter. Note that Moonshot has since shipped newer K2.6 and K2.7 models, so K2.5 is now an earlier release in the line rather than the current flagship.

Released2026-01-27
LicenseModified MIT License
WeightsOpen weights
Parameters1T total, 32B active (MoE)
Context256K
Max output16K
ArchitectureMixture-of-Experts transformer with 1 trillion total parameters and 32 billion activated per token. It uses 384 experts (8 routed plus 1 shared per token) across 61 layers with Multi-head Latent Attention (MLA), and a 400M-parameter MoonViT vision encoder for native multimodal input. The model was built by continued pretraining over roughly 15 trillion mixed visual and text tokens.
ModalitiesText, Vision, Video
StatusAvailable

Benchmarks

  1. SWE-bench Verified76.8%
  2. SWE-bench Multilingual73%
  3. SWE-bench Pro50.7%
  4. Terminal-Bench 2.050.8%
  5. LiveCodeBench v685%
  6. AIME 202596.1%
  7. GPQA-Diamond87.6%
  8. MMLU-Pro87.1%
  9. Humanity's Last Exam (full)30.1%
  10. VideoMMMU86.6%
  11. VideoMME87.4%
  12. MMMU-Pro78.5%
  13. OCRBench92.3%

Scores on a 0–100 scale (25-point gridlines); higher is better. Each benchmark links to its published source.

Pricing

Input$0.60 / 1M tokens per 1M tokens
Output$2.50 / 1M tokens per 1M tokens

Standard list price on Moonshot's Kimi API. Third-party providers vary; OpenRouter lists about $0.375 input / $2.025 output per 1M tokens. Self-hosting the open weights is also an option.

Pricing source ↗

Strengths

  • Strong agentic coding: 76.8% on SWE-bench Verified and 73.0% on SWE-bench Multilingual, competitive with leading proprietary models
  • Open weights under a Modified MIT License that allows commercial use and self-hosting
  • Cost-efficient MoE design that activates only 32B of 1T parameters per token
  • Native multimodal vision (built on a MoonViT encoder) with strong document, OCR, and video-understanding scores
  • Agent Swarm mode that parallelizes work across up to 100 coordinated sub-agents
  • Large 256K-token context window for long documents and codebases

Best for

  • Agentic software engineering: multi-file bug fixes, refactors, and repo-level tasks
  • Visual coding and turning screenshots or design images into working code
  • Long-document analysis, OCR, and structured extraction from PDFs and scans
  • Large-scale parallel research and long-form writing via Agent Swarm
  • Self-hosted deployment for teams needing on-prem or private inference
  • Multilingual coding and reasoning across many programming languages

How to access

ProviderModel ID
Moonshot AI (Kimi) ↗kimi-k2.5
Amazon Bedrock ↗moonshotai.kimi-k2.5
OpenRouter ↗moonshotai/kimi-k2.5

Kimi K2 — every version

The full lineage of the Kimi K2 line, newest first. Every version has its own page — click any to compare specs, benchmarks and pricing.

VersionReleasedContextLicense
Kimi K2.7-Codecurrent2026-06-12256KModified MIT
Kimi K2.62026-04-20Open weights
Kimi K2.52026-01-27Open weights
Kimi K2-Instruct-09052025-09-09Open weights
Kimi K22025-07-11MIT

FAQ

Is Kimi K2.5 open source?

The model weights are openly published on Hugging Face under a Modified MIT License that permits commercial use, so it is open-weight and can be self-hosted. Moonshot also offers it as a hosted API.

How big is Kimi K2.5?

It is a Mixture-of-Experts model with 1 trillion total parameters, but only about 32 billion are activated per token (8 routed experts plus 1 shared, out of 384), which keeps inference far cheaper than a dense trillion-parameter model would be.

What modalities and context length does Kimi K2.5 support?

It natively handles text and images, with experimental video understanding, via a 400M-parameter MoonViT vision encoder. The context window is 256K tokens. It does not support audio input or output.

How much does Kimi K2.5 cost to use?

Moonshot's standard list price on the Kimi API is about $0.60 per million input tokens and $2.50 per million output tokens. Third-party providers vary, and you can also run the open weights yourself.