ChatGPT Chrome Extension is an open-source browser extension that integrates ChatGPT into every text box on the internet. Highlight text anywhere — an email draft, a support ticket, a document — and get ChatGPT’s help rewriting, answering or improving it without leaving the page. One of the earliest extensions of its kind, it has about 3,000 stars on GitHub; the code was last updated in 2023.
The extension adds a small ChatGPT affordance to text fields across the web. Selecting text and invoking the extension opens a prompt box where you can ask a question about the selection or instruct the model — summarize this, make it more professional, reply to this — and see the generated response inline, ready to insert. It connects to ChatGPT using your own signed-in session or API access, so there is no separate account or subscription. The codebase is compact and readable, which made it a popular starting point for developers building their own AI browser extensions during the first ChatGPT wave. As with other unofficial integrations from that era, changes to ChatGPT’s web interface can affect it, but its core idea — an AI assistant embedded in every text box rather than a destination website — anticipated the writing-assistant features now built into major browsers.
The extension is completely free and open source under the MIT license. Any ChatGPT usage goes through your own OpenAI account.
ChatGPT Chrome Extension is for writers, support agents and everyday web users who want quick AI writing help inside the pages they already work in, and for developers looking for a minimal reference implementation of an AI browser extension.