User JavaScript and CSS

User JavaScript and CSS on any website

As of June 2026, User JavaScript and CSS has 200,000 users and a 4.75/5 rating from 656 reviews in the Developer Tools category.

Usersno change0%
200.0K
200,000
Ratingdown 0.2 percent0.2%
4.75
656 reviews
Reviewsup 0.9 percent+0.9%
656
Version
3.1.2
Manifest V3

History

3 snapshots

Tracking since May 5, 2026.

202.3K200.0K197.7KMay 5, 2026Jun 10, 2026
View as table
DateUsersRatingReviewsVersion
May 5, 2026200.0K4.766503.1.2
May 29, 2026200.0K4.766523.1.2
Jun 10, 2026200.0K4.766543.1.2
Now200.0K4.756563.1.2

Permissions & access

Permissions
storagetabsunlimitedStorageuserScriptsscripting
Host access
http://*/, https://*/

Screenshots

User JavaScript and CSS screenshot 1User JavaScript and CSS screenshot 2User JavaScript and CSS screenshot 3

About

Userscript's and userstyle's — simple extension to inject own JavaScript or CSS rules to any page.

Features:
- Instant execution
- Custom libs include
- URL masking allows use one script or CSS on many pages

Documentation: 
https://tenrabbits.github.io/user-js-css-docs/

Change log:
Version 3.1.0
- Starting from Chrome version 138, the method for allowing user scripts in the browser has changed
- Fixed a bug where styles weren't removed when a rule was deleted
- Fixed a bug where not all rules applied to the page were shown in the rules popup

Version 3.0.6 beta
- `try catch` wrapper removed
- CSS injection improved
- added button to save converted URL

Version 3.0.5 beta
- the mode of injection of styles into the DOM has been returned
- minor fixes

Version 3.0.3 beta
- modules are now in the same scope
- CSS injection improvement
- and other minor fixes

Version 3.0.2 beta
- hotfix: fixed bug with registration and deletion of scripts 
- added feature to change start scripts before page loading
- added feature to strictly read URL patterns

Version 3.0.1 beta
- Improved CSS injection
- Fix loading external modules when replacing storage

Version 3.0.0 beta
- The extension has been moved to MV3
- Added option to inject scripts and styles in iframe
- Added the feature of live CSS
- Added the One Dark theme and a few other improvements

Version 2.0.0
- 90% of the code has been rewritten;
- Improved UI;
- Added SASS support;
- Added Prettier formatter
- Other minor improvements

Version 2.0.0
- 90% of the code has been rewritten;
- Improved UI;
- Added SASS support;
- Added Prettier formatter
- Other minor improvements

Version 1.2.8
- Added function for naming rules
- Updated translations

Version 1.2.7
- Updated all extension libraries to current versions

Version 1.2.6
- Fixed error in console "Unchecked runtime.lastError: The message port closed before a response was received"
- Improved domain getter from URL
- Updated Ace Editor and jQuery to latest

Version 1.2.5
- Resolved bug with '@import' and "Auto-important css" feature
- "Auto-important css" feature now disabled by default
- Added feature to exclude URL's by '!' symbol at start
- Updated jQuery and Ace editor to last versions
- Other small fixes

Version 1.2.4
- Added manual cloud sync in testing mode
- Improved "auto-important css" feature
- Other small fixes

Version 1.2.1
- Fixed algorithm of "high priority CSS"

Version 1.2.0
- Added toggle button in site list
- Added documentation tab
- Added 'Vintage mode' option to Ace Editor
- Updated jQuery, Ace Editor to last versions
- Other small fixies

Version 1.1.5
- Returned old method injection and added option to toggle this. Alternative method has feature to avoid CORS issues, but has only DOM access to site (no JS context). Old and now primary method is injecting by <script> tag on site bottom.
- Added scroll past end in editor

Version 1.1.2
- Minor bug fixes

Version 1.1.0
- Added new injection system that increased perfomance
- Added feature: few URLs in one rule (separate by commas)
- Added word wrap setting
- Added CSS auto !important option
- Minor changes

Version 1.0.2
- Hot fixes

Version 1.0.0
- Full redesign of extension
- Added more settings
- Added toggleable counter on extension icon

Version 0.98
- Fix bug that prevent create new rules
- Minor changes

Version 0.96
- Full redesign of extension interface
- 80% code of extension core has been rewritten
- New feature: change URL field and mask with "*" symbol (eg *.expample.com)
- Editor window opens in new tab in split layout
- Disabled autosave feature
- Configurable editor in settings
- New icon

Version 0.94
- Hotfix editor opening bug

Version 0.93
- Fixed a bug where JavaScript is not always inserted in a page
- Outdated processes are disabled

Version 0.92
- Code autosave work on all pages

Version 0.91
- Fix ".co.uk" zone parse
- Other small fixes

Version 0.90
- Improve core
- Add feature to load own libraries

Beta test. If you find any problem or have a question contact me on email.

Technical

Version
3.1.2
Manifest
V3
Size
1.72MiB
Min Chrome
120
Languages
2
Featured
No

Metadata

ID
nbhcbdghjpllgmfilhnhkllmkecfmpld
Developer ID
u77b36e083464e1c28e663add6d8da35f
Developer Email
[email protected]
Created
Apr 17, 2016
Last Updated (Store)
Jul 7, 2025
Last Scraped
Jun 10, 2026
Website
Support URL
Privacy Policy

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Data sourced from the Chrome Web Store · last verified Jun 10, 2026.