Chatgpt.js

Open-source client-side JavaScript library and CLI for interacting with ChatGPT.

Data verified Sep 14, 2026

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Try it free: Free plan
Best for: Browser Extension Developers

About Chatgpt.js

chatgpt.js is a free, open-source client-side JavaScript library (plus an interactive CLI) that lets developers programmatically interact with the ChatGPT web interface and DOM without wrestling with the underlying markup. It's aimed at developers building browser extensions, userscripts, and web integrations, and it's known for being lightweight, object-oriented, and ultra-flexible — the same function can be called multiple ways (e.g. chatgpt.getLastResponse() or chatgpt.response.getLast()). What sets it apart from raw API wrappers is that it drives the existing ChatGPT UI directly, powering practical helpers like auto-continuing cut-off responses, keeping sessions fresh past time limits, and sentiment analysis.

Screenshots

Commonly Cited Strengths & Limitations

Strengths

Free and open source
Lightweight yet performant
Object-oriented and easy to use
Highly flexible, with multiple ways to call the same functions
Popular and actively maintained (2k+ GitHub stars, 200k+ monthly jsDelivr hits)

Common Use Cases

Building browser extensions and userscripts on top of ChatGPT
Integrating ChatGPT answers into search engines like Google and DuckDuckGo
Enhancing email clients such as Thunderbird with ChatGPT
Automating and controlling the ChatGPT web interface programmatically

Details

Pricing Model: Free
Founded: 2023
Category: Developer Tools

Who is Chatgpt.js for?

Browser Extension Developers

Use the library to build ChatGPT-powered browser extensions and userscripts without manually parsing the ChatGPT DOM.

Web Developers

Embed and control ChatGPT within web apps and integrations using flexible, object-oriented helper methods.

Frequently Asked Questions

Is Chatgpt.js free?

Yes, Chatgpt.js is free to use.

Does Chatgpt.js have an API?

Yes, Chatgpt.js provides an API for developers.

Is Chatgpt.js open source?

Yes, Chatgpt.js is open source.

What does Chatgpt.js integrate with?

Chatgpt.js integrates with ChatGPT, jsDelivr, npm.

Who is Chatgpt.js best for?

Chatgpt.js is best suited for Browser Extension Developers, Web Developers.

What can I use Chatgpt.js for?

Common uses for Chatgpt.js include building browser extensions and userscripts on top of chatgpt, integrating chatgpt answers into search engines like google and duckduckgo, enhancing email clients such as thunderbird with chatgpt, automating and controlling the chatgpt web interface programmatically.

How does Chatgpt.js compare to CastReader?

Chatgpt.js and CastReader are both used for developer tools -- specifically browser extension tools. See the full side-by-side comparison for pricing and feature differences.