What is Kimi?
Kimi is a conversational AI assistant from Moonshot AI, a Beijing-based startup founded in 2023 by Yang Zhilin. It first attracted global attention by shipping a 2-million-token context window — at the time the longest of any publicly available chat assistant — and has since built a strong reputation for long-document analysis, file Q&A, and Chinese-language understanding.
Kimi is available free at kimi.com (and at kimi.com/en for English), on iOS and Android, and via the Moonshot AI developer API.
Although Kimi is Chinese-first in tone and training data, English support is now reliable enough for everyday use — including code, structured documents, and technical conversation. The 2M-token window means you can paste in an entire book, a long codebase, or a multi-hour meeting transcript and ask precise questions across the whole thing without manual chunking.
Key features of Kimi
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1
2 million token context window
Kimi's headline feature. Long enough to fit War and Peace, a moderately sized codebase, or several hours of meeting transcripts in a single prompt. Kimi reasons over the full window natively — it can compare passages on page 5 and page 1500 without the answer drifting.
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2
Chinese-first language quality
Trained on a far larger Chinese corpus than Western frontier models. Handles idiom, classical references, and tone for formal Chinese writing better than English-first models translated into Chinese.
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File and document analysis
Drop in PDFs, slides, spreadsheets, or images and ask questions. Kimi reads rendered content rather than just text-extracting, handling tables, diagrams, and scanned PDFs better than naive RAG. Multi-file uploads supported.
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Web search with citations
Fetches live web pages, summarises them, and answers with inline citations. Coverage is strong inside the Chinese internet (Zhihu, Weibo, Baidu Baike) and reasonable for English sites.
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Privacy controls
Free users can opt out of having conversations used for training; paid API users have stricter retention guarantees. Conversations are not visible to other users. (Weigh data residency carefully for sensitive content — servers are in China.)
How Kimi works
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1
Open Kimi in your browser or app
Visit kimi.com (or kimi.com/en) and sign up with email or phone — no Chinese phone number required for the English site.
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Attach files (optional)
Click the paperclip to attach PDFs, Word docs, slides, spreadsheets, or images. Attach multiple files in one go and ask questions across them.
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Ask in plain English or Chinese
Kimi switches language based on your input. For long-document tasks, point to specific sections ("summarise pages 200–250") for better output quality.
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Toggle web search for live data
Enable Web Search for current-events queries — Kimi fetches sources, summarises, and cites URLs inline. Without the toggle, it answers from training data only.
Real use cases
Long-document analysis
Legal, academic, finance professionals
Upload entire contracts, research papers, or regulatory filings and interrogate them end-to-end — no manual chunking needed.
Chinese writing assistance
Students, writers, professionals
Draft, proofread, and edit Chinese content with idiom-level accuracy that Western-first models typically miss.
Research & fact-checking
Journalists, researchers
Enable web search for live citation-backed answers across Chinese and English web sources.
Code generation & review
Developers
Paste large codebases in one prompt. Ask it to review, refactor, or explain sections across the entire project at once.
Pros and cons
Pros
- 2M-token context window — best-in-class for long docs
- Chinese-first language quality
- Strong file and document analysis
- Free tier with generous limits
- Web search with inline citations
Cons
- Chinese-first — English lags behind Western models
- Smaller ecosystem and integrations than ChatGPT
- Data residency in China — sensitive content caution
- Less known outside China
Kimi pricing
| Plan | Price | Includes |
|---|---|---|
| Free | $0 | Daily message cap, file uploads, 2M-token context, web search |
| Pro | ¥99/month (~$14) | Higher daily quotas, priority access, newer model snapshots |
| API (Moonshot AI) | Per token | Pay-as-you-go, multiple model sizes, long-context variants |
Check latest API rates at platform.moonshot.cn.
Alternatives to Kimi
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Google Gemini — also offers a 2M-token context window with broader app integrations.
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Claude — 200K-token context with strong long-form writing and analysis.
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ChatGPT — broadest English-language assistant with the largest ecosystem.
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DeepSeek — Chinese-market peer with similar long-context capabilities and a strong open-source model.