extension-js/extension.js
The cross-browser extension framework. observed · 2026-08-28
Health v2 · maintenance only
95/100
- Activity 99
- Release rhythm 87
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: 0
- age_days: 2141
- days_rel: 11
- days_push: 9
- n_releases_24m: 108
Adoption not part of the score
5069 stars · 131 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded
Extension.js is a zero-config framework and CLI for building cross-browser extensions for Chrome, Edge, Firefox, and Safari from a single codebase. It handles manifest compilation with browser-prefixed fields, hot module replacement for extension scripts, per-browser build outputs, and store-ready packaging.
Use cases
- build a chrome extension with react and typescript
- ship one extension to chrome edge and firefox from a single codebase
- scaffold a browser extension project from a template
- get hot reload for content scripts and background service workers
- package an extension as a zip for the chrome web store
- run a github extension sample without cloning or configuring
- handle manifest v3 differences between chromium and firefox
When to choose
- you want zero build configuration for a new browser extension
- you need to target multiple browsers from one manifest.json
- you want HMR for popup, options, content, and background scripts
- you prefer first-class TypeScript, React, Vue, Svelte, or Preact support
- you want to prototype by running GitHub extension samples directly
When to avoid
- you need an all-in-one platform with store publishing and updates built in
- your project is already deeply invested in another bundler like webpack or Vite plugins
- you need to support browsers or engines outside the Chromium and Gecko families
- your environment cannot run Node.js 22.12 or newer
Facets
framework · maturity active
build-tool cli browser-extension developer-tools scheduling browser-extensions web-development developer-tools cross-platform browser browser-extension cli cross-platform manifest-v3 hot-module-replacement zero-config webextension chrome-extension firefox-extension safari-web-extension scaffolding typescript react vue svelte preact cross-browser nodejs
10 sources
- readme: https://github.com/extension-js/extension.js · fetched 2026-08-28 · 59af279a3bd0
- homepage: https://extension.js.org · fetched 2026-08-29 · a97234523067
- site_page: https://extension.js.org/docs · fetched 2026-08-29 · c0765367093d
- site_page: https://extension.js.org/docs/getting-started/templates · fetched 2026-08-29 · 922ebaca3ea8
- site_page: https://extension.js.org/docs/ai-access · fetched 2026-08-29 · add27b29f786
- site_page: https://extension.js.org/docs/getting-started/immediately · fetched 2026-08-29 · b906a9980451
- site_page: https://extension.js.org/docs/features/browser-specific-fields · fetched 2026-08-29 · a220c1c9781c
- site_page: https://extension.js.org/docs/getting-started · fetched 2026-08-29 · 470eb0318504
- site_page: https://extension.js.org/docs/features/cross-browser-compatibility · fetched 2026-08-29 · 877f888ea374
- site_page: https://extension.js.org/docs/implementation-guide/manifest-json · fetched 2026-08-29 · 2535938d5d11
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| extension-js/extension.js | main | 95 |
For agents
markdown · JSON · MCP: product_card(name="extension-js/extension.js")
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem