Most AI chatbots start to lose the thread of a conversation after a few pages of text. Kimi AI, from the Chinese startup Moonshot AI, does not. It can chew through roughly one million tokens in a single session – enough to hold the full text of Leo Tolstoy’s War and Peace and still answer questions about a detail buried on page three. That kind of memory changes what an assistant can actually do, and it has made Kimi one of the most interesting AI products of the year.
What is Kimi AI?
Kimi is a free AI assistant, launched in late 2023 and built by Moonshot AI, a Beijing-based company founded by Yang Zhilin, a former Google Brain researcher. It started as a Chinese-language chatbot, but it now handles English fluently and is available through a web app, Android, and iOS. Unlike many standalone chat interfaces, Kimi is designed to connect to the internet for real-time research, read uploaded files such as PDFs, Word documents, and spreadsheets, and maintain long, free-flowing conversations.
The 1M-Token Context Window That Changes the Game
Context window is the amount of text a model can remember in a given session. OpenAI’s GPT-4 Turbo handles 128,000 tokens. Anthropic’s Claude 3.5 Sonnet offers 200,000. Kimi launched with 200,000 and then scaled to 1 million tokens in early 2024. One million tokens is roughly 750,000 English words – around 1.5 copies of War and Peace. That means you can paste an entire coding repository, a year of customer support logs, or a 1,000-page legal contract into the chat and ask specific questions without chopping the document into pieces.
What can you actually do with that much context?
- Summarise a full book and still cross-check exact quotes from different chapters.
- Audit a large codebase for bugs and security issues without splitting the files.
- Compare data across 50 quarterly reports to spot trends that get lost in single filings.
- Draft a reply to a 300-email thread where every previous exchange matters.
In practice, it means Kimi can act like a research assistant that has actually read everything you’ve given it – not just skimmed the first few paragraphs.
How Kimi Compares to ChatGPT and Claude
On standard reasoning and coding tests, Kimi holds its own. Its English output is slightly less polished than GPT-4’s, but it’s noticeably better in Chinese. Where Kimi genuinely wins is in long-context tasks. ChatGPT starts to lose fine details after about 50,000 tokens, while Kimi can still recall a specific sentence from a million-token prompt. The trade-off is speed – processing that much text takes time – and a few rough edges in non-English languages.
Internet search is built in
Many chatbots offer browsing as a premium feature. On Kimi, it’s free and automatic. The model can search the web to verify facts, pull recent news, and cite its sources. That makes it handy for research without the usual copy-paste loop.
And it’s completely free
For now, Kimi has no paywall. You get the full million-token context window and web search without a subscription. Moonshot could add usage limits later, but the fact that a startup is giving away what Western labs charge £20 a month for is a sign of how competitive the AI market has become.
Practical Uses: Where Kimi Shines
The clearest use case is research. If you’re buried in PDFs, you can upload a whole folder and have Kimi produce an annotated literature review. In a test, a user loaded the full text of Anna Karenina – over 800,000 tokens – and asked about the colour symbolism in Part Two. Kimi returned three detailed paragraphs with direct quotes, something ChatGPT couldn’t do without slicing the novel into pieces.
More broadly, people are using Kimi for:
- Academic literature reviews and annotated bibliographies.
- Due diligence in finance, including reading long prospectuses and contracts.
- Bug hunting in large codebases where context matters.
- Meeting transcript analysis for HR and legal teams.
- Historical document analysis, from old newspapers to family archives.
- Competitive research across hundreds of pages of rival reports.
Because the model can access the live web, it also works as a fact-checking companion – a feature that’s usually locked behind paid tiers in Western chatbots.
The Bigger Picture: China’s AI Assistants Are Coming for the West
Kimi is not an island. Moonshot is part of a wave of Chinese AI labs – Alibaba, Baidu, Zhipu, and others – that are moving from copycats to challengers. As China’s Alibaba takes another swipe at America’s AI supremacy, the competitive balance is shifting. In one recent benchmark, Alibaba’s Qwen model outperformed several Western rivals on math and reasoning tasks, and its underlying costs are a fraction of the West’s. That push has engineers and investors paying attention to the whole Chinese ecosystem, not just the American giants.
Safety, Hallucinations, and the Long-Context Trap
A model that remembers one million tokens also remembers your mistakes. Kimi is better than most at not inventing references for huge documents, but it’s not immune to hallucination. In one test, it mixed up two similarly named characters from a novel and once fabricated a quote from a legal transcript. The bigger worry is when wrong answers come from enormous, authoritative-looking context. If a user asks Kimi to summarise 10,000 pages of medical research, a single invented statistic could end up in a decision-maker’s report without further checks. That’s not unique to Kimi, but longer context makes errors harder to spot.
And as models become more autonomous, the stakes rise. For years, discussions of rogue AI have sounded like distant warnings, but the technology to act on its own is already here. A model with a million-token memory and live web access is precisely the kind of tool that demands careful handling. Researchers have also noted that the safety tests we use to evaluate these models are becoming a safety risk in themselves, since passing a test often gets mistaken for real-world safety. That doesn’t mean Kimi is dangerous, but it’s worth keeping a skeptical eye on outputs that come from enormous prompts.
How to Try Kimi AI Today
Kimi is available as a web app at kimi.com, and as an app on iOS and Android. You can start chatting right away without an account, though creating one unlocks file uploads and browsing history. The free tier currently includes the full 1M-token context window, though Moonshot says usage limits may be added later. If you spend your days reading long reports, coding across huge codebases, or just want a chatbot that won’t forget your instructions halfway through, it’s worth a shot. And if you’re curious how the wider Chinese AI ecosystem is developing, keeping an eye on Moonshot’s next moves is a good place to start.