- Apply any CSS rules for any websites, including iframes.
- Whitelist and Blacklist functionality
- Apply CSS rules to specific URLs, Domains or Globally
- Syntax highlighting & line numbers
- Update without page refresh

CustomCSS Injector: Control the Look of Your Web Pages
CustomCSS Injector is a unique Firefox add-on, powerfully designed to let you customize the appearance of any website as per your preference. It provides you with the power to change colors, backgrounds, resize elements and even hide those you find intrusive, all by applying your own CSS rules. The add-on includes features such as applying CSS rules based on specific URLs, Domains or Globally, coupled with a whitelist/blacklist functionality. Further enhancing your experience are syntax highlighting and line numbers courtesy of PrismJS, making your coding readable and accessible.
Add-on stats
Manifest V2
Weekly download count: 30
Firefox on Android: Yes
Permissions:
- storage
- <all_urls>
- contextMenus
- notifications
Size: 44.31K
Email: br*****@gmail.com
URLs: Website
Full description: See detailed description
Ranking
Other platforms
Not available on Chrome
Not available on Android
Not available on Edge
User reviews
Pros
- Works great
- Powerful and easy to use
- Ideal for working in website backends
- Lightweight and straightforward implementation
Cons
- CSS inject timing is too late, affecting page load
- Invalid data error when saving CSS rules
Most mentioned
- Works great
- Powerful and easy to use
- Issues with CSS rule saving
User reviews
Fonction mais comment ajouter pour differents site ?
by Firefox user 17672785, 2024-11-19
by Firefox user 14033823, 2022-05-10
Add-on safety
Risk impact
CustomCSS Injector requires a few sensitive permissions. Exercise caution before installing.
Risk impact analysis details
- Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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- Low ******* ****** ** *** ********* ********
Risk likelihood
We don't have sufficient data to confidently determine the risk likelihood of CustomCSS Injector. Use it at your own risk.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
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