Create cross-browser extensions with no build configurated. Created by @cezaraugusto
Browsers and terminals
Joined September 2018
- Tweets25
- Following30
- Followers115
- Likes33
Extension.js retweeted
hello! I maintain Extension.js. one manifest.json runs in Chrome, Edge, Firefox and Safari and the extension reloads when you save
npx extension@latest create my-extension --template=react
same command with vue, svelte, preact or typescript. your manifest stays yours, no config
one manifest.json, four browsers
Extension.js runs the same extension in Chrome, Edge, Firefox and Safari, reloads it when you save, and asks for no config
4.1.33 is out. six posts on what it does, with the real commands
browsers by name
--browser=chrome, edge, firefox, brave, opera, vivaldi, yandex, waterfox, zen and floorp each run their own app. Safari builds through Xcode
Deno and Bun run the CLI too: deno run -A npm:extension@latest, bunx --bun extension@latest dev
that is the tour
docs and the showcase of extensions shipped on it: extension.js.org
source: github.com/extension-js/exte…
questions here or in the Discord linked from the docs
September 2026 roundup is on the blog
- showcase page with five shipped extensions
- Deno and Bun run the CLI
- Floorp and Zen by name
- a content script edit reloads one copy, not two
- Rspack pinned, upgrade if you are on 4.1.18 to 4.1.23
extension.js.org/blog/septem…
Extension.js 4.1.33 is out!
- Safari dev runs leave your own Safari alone
- sidebar templates read the open tab's title
- side_panel and sidebar_action translate both ways
- @Floorp_Browser is a first class target, --browser=floorp
github.com/extension-js/exte…
tip: add .md to any page on extension.js.org and you get its markdown copy, ready to paste into your AI tool of choice
or point it at extension.js.org/llms.txt and it finds every docs page from there
a lot of who reads the Extension.js docs is not a person anymore. it is AI tools reading the .md and llms.txt copies Mintlify builds for every page
thanks @mintlify for that and for hosting the docs in your open source program. your analytics told me
extension.js.org
we made a page for the extensions people ship with Extension.js
Better Lyrics, Star Citizen Box, Simple Virtual Keyboard, Better Trello and Send to PocketBook. shipped products, all in the stores
extension.js.org/showcase
Extension.js retweeted
started writing a weekly journal about my work
starting with Extension.js: how it began, why it exists, and what it’s becoming
cezaraugusto.substack.com/p/…
it's been a while but Extension.js is alive and well! version 3.10.2 is out along with a brand new documentation extension.js.org
Extension.js retweeted
🚀 Big shoutout to @darkreaderapp for their financial contribution to @extensionjs via @opencollect. Your contribution helps me working even more for developers looking to make it very easy to develop cross-browser extensions. Thank you! #opensource
Extension.js retweeted
Built using @extensionjs
I just published an extension to inspect @lexicaljs editor state from your browser.
dub.sh/lexical-devtools
Extension.js retweeted
@extensionjs v1.6.0 is out! ✨
Full #Vuejs support, default auto-reload of static assets, and more. Bold community contributions this time! Changelog: github.com/cezaraugusto/exte…
Create your Vue Extension now:
npx extension create my-vue-ext --template=vue
@extensionjs 🤝 @vuejs
🧩🤝🦊
@firefox support is live in Extension.js 🚀🚀🚀
Here is a sample run using firefox-code-search sample from @MozDevNet. Starting on v1.5.0, developers can use Extension.js to run Mozilla Add-Ons.
Try it now! 🧩
npx extension@latest dev github.com/mdn/webextensions… --browser=firefox
Extension.js retweeted
🔌 extension.js by @cezaraugusto: 0-Config, Cross Browser Extension Dev Starter. Featured in @JavaScriptDaily (javascriptweekly.com/issues/…). & @FrontendDaily (frontendfoc.us/issues/641).
🔗 extension.js.org/
Extension.js retweeted
extension.js.org: the "@nextjs of browser extensions". Built-in support for @reactjs and @typescript.
▲ ~/ npx extension dev
▲ ~/ npx extension build
▲ ~/ npx extension start
@cezaraugusto is the hero this world needed.
ALT Two browser windows displaying information about the "my-extension" Chrome extension. extension-create >>> my-extension (v1.0) (webpack 5.89.0) compiled successfully in 2565 ms Name: my-extension Description: An extension template using web technologies. Version: 1.0 Size: 557.5 kB ID: phpnchffjmbiphhloeogmpfjhiachnek (dynamic) Permissions: webTab,pageOverride (dev only), scripting (dev only) Settings URL: chrome://extensions/?id=phpnchffjmbiphhloeogmpfjhiachnek chrome-browser >>> Running Chrome in development mode. Browser extension enabled. >>> Running Edge in development mode. Browser extension enabled.
Extension.js retweeted
w00t!! Extension.js is currently ranking #1 on Hacker News news.ycombinator.com
