Fixed-width and CSS Annihilator

Provides key shortcuts for removing fixed-width page styling, un-sticking "fixed" elements and disabling CSS completely.

Usage

Key shortcuts:

  • Shift+Alt+X: De-widthify current page (and un-stick fixed page elements)
  • Shift+Alt+A: Disable all styles (CSS) on current page
This addon does not work well on some websites. The web is too complex to make a perfect solution.

To "undo" any changes made to a page: refresh the page. No changes are permanent.

De-widthify Many websites restrict the width of their text columns. Some people find this unergonomic, especially on small laptop screens and/or articles that require lots of scrolling.

This addon subverts the most common way websites implement fixed-width text columns: margins in CSS. When you press Shift+Alt+X all page margins are nullified.

This solution is not 100% reliable. Some websites will work fine, others may look ugly or break. It's impossible to make a page-modifying solution that works on every possible site out there.

Un-sticky "position:fixed" elements Many websites contain large headers or footers that are "fixed" in place even when you scroll down. This can be unergonomic on small screens.

This feature naively disables all such elements. A small amount of extra vertical whitespace may be left behind due to styling technicalities.

Disable CSS This features disables all site stylings, leaving you with your browser's default CSS styles instead. A few extra (minor) rules are added (eg to prevent images exceeding your screen width).

Useful for when:

  • A website is difficult to read
  • A website is hiding parts of or the whole page from you
The default CSS styles provided by your browser are generally considered easy to read, however they can be further customised via UserChrome.css.

Caution: some websites intentionally hide elements they do not want you to interact with. I do not recommend using interactive sites with CSS disabled, it can be a very confusing experience.

Future Extension Ideas

  • Options dialog: configurable "extra-CSS rules" to be added when you disable CSS
  • Options dialog: configurable CSS for the de-widthify feature
  • Options dialog: configurable key shortcuts
  • Toolbar button
  • General goal: make a more configurable alternative to "Firefox Reader Mode"
I am unlikely to implement these features unless nagged or helped :)
Manifest V2 Add-on
By:
Veyrdite
Daily users:
37 -2
Rating:
4.50
(6)
Version:
1.1.0 Last updated: 2019-08-03
Version code:
4827664
Creation date:
2018-11-29
Risk:
Very low risk impact Low risk likelihood
Permissions:
  • activeTab
Size:
33.29KB
Email:
no*****@halestrom.net
Full description:
See detailed description
Source:
Firefox Browser Add-ons
Data ingested on:
2025-07-18

User reviews

Thanks for trying. I hate these websites that show very wide lines of text that do not reflow. They think they are the only website in the world. I might want to look at another window side by side. Didn't work for me on Amazon, for the Editorial Reviews section. Shift-Option-X did nothing, A broke the page with lots of overlapping text and images. I'm on Macos, so I used Shift-Option-X and A since there is no Alt key.
by Fi*****, 2025-04-15

by 天灭*****, 2025-04-15

by 退出*****, 2025-03-11
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.

Fixed-width and CSS Annihilator does not require any sensitive permissions.

Risk impact analysis details
    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.

    Fixed-width and CSS Annihilator has earned a fairly good reputation and likely can be trusted.

    Risk likelihood analysis details
    • High This extension has low user count. Unpopular extensions may not be stable or safe.
    • Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
    • Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
    • Good **** ********* *** **** **** *******
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