# Tampermonkey/tampermonkey

Tampermonkey is the most popular userscript manager, with over 10 million users. It's available for Chrome, Microsoft Edge, Safari, Opera Next, and Firefox.

Repository: https://github.com/Tampermonkey/tampermonkey
Canonical: https://ross.abutalabs.com/products/tampermonkey
Language: JavaScript
License: GPL-3.0
License Family: copyleft
Last push: 2025-03-30T16:01:47+00:00

## Health v2 (maintenance only)
Score: 39/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 14, release rhythm 35, longevity 100
- inputs: {"age_days": 4188, "days_push": 521, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5692, forks 561 (observed 2026-08-28T04:09:28.004532+00:00)

## What it is
Tampermonkey is the most popular userscript manager, available as a browser extension for Chrome, Edge, Safari, Opera, and Firefox. It lets users install, manage, edit, and sync userscripts that customize web page behavior, supporting Greasemonkey-compatible metadata and GM_* APIs.

## Use cases
- manage and edit userscripts in the browser
- enable or disable userscripts with two clicks
- sync userscripts between browser instances
- customize website appearance and behavior with scripts
- find userscripts matching the current page URL
- run Greasemonkey-style scripts with GM_* API support

## When to choose
- you want to run or manage userscripts across Chrome, Edge, Firefox, Safari, or Opera
- you need full unsafeWindow access and GM_* function support
- you want to sync scripts between multiple browser instances

## When to avoid
- you need the source code of recent versions - new versions are proprietary, only up to 2.9 is GPL open source
- you want a server-side or Node.js scripting tool rather than a browser extension
- you need Manifest V1 support for very old Chromium versions without using the legacy build

## Facets
- artifact type: plugin
- maturity: active
- function: developer-tools, plugin-system, workflow-automation, web-scraping
- domain: browser-extensions, developer-tools, web-development
- platform: browser, browser-extension, cross-platform
- tags: userscript-manager, greasemonkey-compatible, browser-extension, script-injection, gm-functions, automation

## Member repositories
- Tampermonkey/tampermonkey (main) score 39

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:28.004532+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:53:43.757530+00:00, confidence not recorded.
  - readme: https://github.com/Tampermonkey/tampermonkey (fetched 2026-08-28T04:09:28.004532+00:00, sha 3456f4680aa4)
- Data as of 2026-08-30T08:39:29.467469+00:00.