LocalChat — local AI chat in Chrome

About

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