Tampermonkey

Tampermonkey is the world's most popular userscript manager.

Tampermonkey is the world's most popular userscript manager, boasting over 10 million weekly users. Compatible with Chrome, Microsoft Edge, Safari, Opera Next, and Firefox, it offers an intuitive interface for managing and customizing userscripts. Key features include a comprehensive overview of active scripts, an integrated editor, ZIP-based import/export with cloud support (Google Drive, Dropbox, OneDrive), automatic update checks, and synchronization across browsers and cloud storage.

The extension ensures compatibility with Greasemonkey up to version 3.x and offers experimental support for version 4.x. For users seeking the latest features, a frequently updated BETA version is also available. Tampermonkey streamlines the userscript experience, making customization and script management seamless and efficient across multiple browsers.

Manifest V2 Add-on
By:
Jan Biniok
Daily users:
696,577 -4,678
Rating:
4.70
(5,150)
9 new ratings
Version:
5.3.3 Last updated: 2024-12-20
Version code:
5861448
Creation date:
2016-02-01
Risk:
Very high risk impact Low risk likelihood
Permissions:
  • alarms
  • notifications
  • tabs
  • idle
  • webNavigation
  • webRequest
  • webRequestBlocking
  • unlimitedStorage
  • storage
  • contextMenus
  • See more
Size:
1.58MB
URLs:
Website ,Privacy policy
Full description:
See detailed description
Source:
Firefox Browser Add-ons
Updated:
a day ago

Other platforms

Tampermonkey (v5.3.3)
11,000,000 4.73 (72,311)

User reviews

Tampermonkey is a powerful and reliable Firefox add-on that empowers users to customize web pages via userscripts, enhancing their browsing experience with new features and cleaner interfaces. It offers a solid built-in editor and enjoys strong community support. However, some users have experienced installation problems involving corrupted files.
Pros
  • Allows customization of websites through userscripts
  • Has a robust built-in script editor with syntax highlighting and debugging
  • Enables enhancement of web browsing experience by adding new features or blocking unwanted content
  • Reliable and performs consistently across browsers
  • Supported by a large and active community providing ready-made scripts
Cons
  • Installation issues reported (possibly corrupted files)
Recent reviews
by zh*****, 2025-06-22

by Mi*****, 2025-06-22

good
by Fi*****, 2025-06-21
View all user reviews ›

Extension safety

Risk impact
Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Tampermonkey requires a lot of sensitive permissions. Exercise caution before installing.

Risk impact analysis details
  • Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
  • Critical ****** ****** ** *** ********* ****** * *********** ******** **** ** ** *** ******* *** ****** **** **** *** ******* *****
  • High ****** *** ********* ** ******* *** ******* ******* ** ****** *** *** ******** ******
  • High ****** ********* ** * ****** ******** ******** ********** * ******* ******* *****
  • High ****** ******* *** ********* ********* ******** ***** *** ** ********** ****** * ******** ******* *****
  • Medium ******* ******* ************* ***** *** ** ******* *** **** ******* ****** ******** *******
  • Medium ****** ********** ** ******** ********** *** ********* ******* ******** ****** ******** ****** ********
Risk likelihood
Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Browser Add-ons, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Tampermonkey has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details
  • Low This extension was updated more than 6 months ago. Older versions are more likely to be stable and safe.
  • Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
  • Low **** ********* *** **** **** ****** ******* ********** **** ****** ** ** ****** *** *****
  • Good **** ********* *** **** **** *******
Upgrade to see full risk analysis details

Compare add-ons

Similar add-ons

Here are some Firefox add-ons that are similar to Tampermonkey:

Popular extensions / apps

Here are some popular extensions / apps that you might be interested in: