Best Open-Source Browser Extension Tools in 2026

Browser Extension lists open-source projects for extending or controlling browsers. MetaMask Extension is a crypto wallet for Ethereum sites and dApps; Bitwarden Client Apps include a browser extension for vault access and password management; Plasmo is a framework for building and deploying browser extensions. Use this category for WebExtensions, wallets, and browser tooling.

The most popular open-source Browser Extension tool by GitHub stars is Puppeteer(94.1k stars), followed by WebTorrent(30.9k stars)and Brave Browser(22.1k stars). This page lists the top 16 of 16 browser extension tools in the directory, ranked by community adoption.

Quick comparison

Best open-source Browser Extension tools in 2026, ranked by GitHub stars
#ToolStarsLanguageLicense
1Puppeteer

A Node library providing a high-level API to control headless Chrome or Firefox browsers over the DevTools Protocol.

94.1kTypeScriptApache License 2.0
2WebTorrent

⚡️ A powerful streaming torrent client that allows seamless streaming of torrents on the web.

30.9kJavaScriptMIT License
3Brave Browser

A secure and fast web browser for Android, iOS, Linux, macOS, and Windows, with privacy features.

22.1kJavaScriptMozilla Public License 2.0
4Neko

A self-hosted virtual browser that runs in Docker, leveraging WebRTC for video streaming and remote collaboration.

20.4kGoApache License 2.0
5FreeTube

An open-source YouTube client focused on privacy, allowing users to watch YouTube videos without being tracked.

16.9kJavaScriptGNU Affero General Public License v3.0
6MetaMask Extension

The MetaMask browser extension is a user-friendly crypto wallet facilitating secure interaction with Ethereum blockchain-enabled sites, decentralized applications (dApps), and Web3 projects directly from your browser.

13.0kTypeScriptOther
7Plasmo

The Browser Extension Framework for building, developing, and deploying modern, feature-rich browser extensions efficiently.

12.7kTypeScriptMIT License
8Bitwarden Client Apps

Bitwarden client applications for web, browser extension, desktop, and CLI offering secure vault access and password management.

12.6kTypeScriptOther
9BrowserSync

A tool to keep multiple browsers and devices in sync while building websites. Enables live reloading and synchronization across different devices.

12.2kJavaScriptApache License 2.0
10Wxt

⚡ Next-gen Web Extension Framework for building modern web extensions with ease and efficiency.

9.6kTypeScriptMIT License

All 16 Browser Extension tools

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Frequently asked questions

What is the best open-source browser extension tool in 2026?

Puppeteer leads by GitHub stars(94.1k). A Node library providing a high-level API to control headless Chrome or Firefox browsers over the DevTools Protocol.

Are these browser extension tools free?

Yes. Every tool on this list is open source and free to use in your own projects. Many can be self-hosted.

How is this list ranked?

Tools are ranked by GitHub star count, a strong proxy for community adoption and active maintenance. Star counts are refreshed regularly.

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