LocalChat — local AI chat in Chrome

LocalChat is a private AI assistant that runs entirely on your computer using Chrome’s built-in Gemini Nano model (Prompt API). Ask questions, summarize web pages, analyze documents, or describe images—without sending your chat to AI4Context servers. Click the LocalChat icon to open a resizable chat window. Your conversations stay on your device. WHAT YOU CAN DO • Chat locally — Stream answers from Gemini Nano in Chrome • Use this page — Attach visible text from the active tab (with your confirmation) to summarize or ask questions • Use selection — Highlight text on a page and attach only that fragment • Attach document — Pick a local PDF or text file (.txt, .md, .csv, .json, and more); text is extracted on your device • Attach image — Pick a PNG, JPEG, WebP, or GIF for on-device multimodal analysis • Saved history — Restore past conversations stored locally on this device • New chat & stop — Start fresh or cancel a reply in progress • English & Spanish UI HOW IT WORKS Open LocalChat from the toolbar. Optionally attach context: a web page, a text selection, a document, or an image. Type your question and send. Gemini Nano processes your request on-device. After the model is downloaded once, chat can work offline for local inference. The first download requires an internet connection. PRIVACY BY DESIGN • Your messages are processed locally by Chrome’s on-device AI • LocalChat does not upload your conversations to AI4Context • Page text is read only when you click Use this page or Use selection • Files are read only when you choose them with Attach document or Attach image • Conversation history is saved in chrome.storage.local on your device—not synced to our servers • Google Chrome manages the on-device model; see Google’s built-in AI documentation for model download and updates REQUIREMENTS • Chrome 138+ on desktop (Windows 10/11, macOS 13+, Linux, or Chromebook Plus) • Hardware and disk space per Chrome’s Prompt API requirements • Gemini Nano must be available and downloaded on your system WHAT LOCALCHAT DOES NOT DO • Does not browse your files or folders without you picking a file • Does not monitor tabs or pages in the background • Does not read restricted pages (e.g. chrome://, Chrome Web Store) • Does not run terminal commands or access other apps • Does not auto-fill web forms (not supported yet) PERMISSIONS (WHY WE ASK) • Storage — UI language preference and locally saved conversations • Active tab, scripting, tabs — Only when you choose Use this page or Use selection, to read visible or selected text from that tab once Part of the AI4Context extension family — honest, privacy-first tools for everyday browsing. Questions or feedback: github.com/mapicallo/localChat