nay-cat/chromechat

ChromeChat is a chat application that runs an AI model directly inside your browser. Once you visit the page and let it set up, you can keep talking to the AI even with no internet connection. There is no server behind it and no API key to manage, since the model lives on your own machine. The AI used is either Google's Gemini Nano on Chrome or Microsoft Edge's Phi-4, both of which the browsers can download and run locally. To use it, you need a recent version of Chrome (148 or later) and about 4 GB of free storage for the Gemini Nano model. You also need to turn on a browser flag at chrome://flags/#prompt-api-for-gemini-nano and have a compatible GPU and CPU. Edge users need a similar flag for its Phi model, which takes around 2.4 GB instead. The page checks compatibility automatically when you first open it and walks you through downloading the model. After that, the chat works offline. The chat itself offers normal features for this kind of tool. It saves your history locally so you can return to old conversations, lets you attach images, PDFs, text files, and code files, and renders Markdown with syntax highlighting. You can also export a chat to a file with the .crchat extension and import it back later. The app supports English, Spanish, and Japanese, and you can customize the AI's name, your name, and the system prompt that shapes how it answers. Data storage stays on your device. Chat text goes into LocalStorage, which has a 5 MB cap, so the oldest chats are pruned when it fills up. File and image attachments go into IndexedDB, which handles larger binary data. When you export a chat, attachments are bundled into the file so the export is self-contained. Nothing leaves the browser, though the author jokes about the small caveat that the whole thing still runs inside Google Chrome.