Most simple，但是比Stylish更管用。

Excellent, thanks a lot for programming this! I am using for not other particualr reason than to better distinguish "Il1" in URLs the free font Atkinson Hyperlegible, but this breaks my FritzBox-Website as well a other web sites. This switch then comes in handy!

Essential addon in all of my Firefox variants. Actually I LOVE all of this author's "toggle" addons.

Toggling website fonts (and toggling Zoom-Text-Only -- see addon here: https://addons.mozilla.org/en-US/firefox/addon/toggle-zoom-text-only/) really helps with smaller screens, or for hard-of-seeing folks, or you're just picky about nice clear fonts. For many years I've been screwing with my browser fonts because I HATE Times New Roman, and hate small text. That font just jangles my nerves it's so spiky and unclear. As a result my webpages are often not rendered properly. These two toggle buttons really help with straightening out text on-the-fly when you need it.

Simple, yet effective.

Marvelous. Saves so much time and frustration :)

Does exactly what I was looking for! I put it under Firefox's overflow menu and now it's available whenever I need it. I have custom fonts set for serif and sans-serif which are more legible than the defaults (let alone what many sites override them with) so this works wonders for me.

Note this addon works by toggling the actual browser setting, so it affects all tabs/windows at once—no per-page control. This isn't an issue for me, but it's something to keep in mind (certain web apps / document editors may not function fully without enabling custom fonts—that's one of the things which makes a toggle addon like this so useful).

Works like a charm. 1 Click solution

Exactly what I needed!

I recently updated Firefox browser to the latest version (89.0) on my Linux distro, and that seems to have somehow messed up the size of the fonts on several websites, including Gmail - making them very tiny.

Tried various methods, but nothing worked until I came across this extension.

I'm now able to easily enable or disable website defined fonts instead of having to navigate to Firefox's "Language & Appearance" settings each time to make the change.

Thank you so much, Mr. Manuel Reimer, for this simple but incredibly useful tool.

This is nearly exactly what I needed. I like using a font of my own choosing in most places, but that breaks Google Docs. The one thing that would make it better would be an option to set it for specific websites, but the extension is so simple and easy to use that that's barely an issue.

When you print a Page to a virtual printer and, instead of a lean text PDF, you get a huge file with now-searchable images, it means the Page you are trying to convert to PDF uses some fonts that Firefox cannot handle well as proper text, so it shoves screenshots of the pages into the printer. Luckily, most of the times that can be solved turning off external font usage, but it's utterly annoying to go to Tools-Options-General-Languages-Fonts-Advanced and check/uncheck the option there just to try it... Thus, this extension may not seem such a big deal, but the small thing it does, it does very well and when in a hurry, it saves more than time, it saves your mental sanity!

I like this add-on, but cannot figure out (a) what the keyboard shortcut is; (b) how to edit said keyboard shortcut. Advice?

Very handy; apparently it's impossible to do this per-site, so this is a great workaround for those few sites that need their own fonts.