Thanks to Jarrad, this extension is very useful.
It has only one problem: compatibility with new Firefox for android. I added this extension to new Firefox, but it didn't work :(

Kind of crazy that you need an add-on for this sort of thing. Anyway, works great. Thanks Jarrad!

Breaks some sites:
1) http://forum.mozilla-russia.org - spoilers in topics don't work.
2) Chrome addons webpages (for example, https://chrome.google.com/webstore/detail/fit-to-width/dfdmbpdbpocelpgahddghhkomnefchkl )

Хорошо работает на большинстве страниц, проблема с горизонтальной полосой прокрутки становится редкой. Подобные возможности должны быть встроены в браузер.
Но ломает некоторые сайты (см. выше).

Just a lifesaver!
This functionality, however, should be in Firefox by default.

Superb extension to read anything

This is inferior compared to the other for to width add on that is no longer available. In this version it does everything automatically so basically if you zoom in on a page that already is good but you just want to see the letters a little bit larger it'll try to resize the entire page. This ends up throwing off the entire page and you actually can't even lose your place of where you're eating. The other version which I cannot find currently was where you tap to adjust the font to fit the screen and that worked really well because it would allow you to manage which things get adjusted instead of the entire page automatically

Cool. Its working on my android phone.

Doesn't work at all :(

Doesn't work for me on my Samsung 7

this is an essential addon!
Thank you!

Works on most site but why don't it work on reddit?

Doesn't work. Tried to word wrap the view-source of a web page

please, update this app!!!!
this is the best from other!
please, please, please

Wonderful! This functionality really should be built into Firefox.

Question: Will you be updating it as a webextension for Firefox for Android 57(Quantum) by November 14 or perhaps sooner for Firefox for Android Beta?
Please!

sad that Firefox's instability will always mean being three steps behind. every single thing breaks every single instance the app is updated, and it was only a matter of time before 90% of the vital add-ons that practically cut off a major portion of work for the dev team was dropped.

such a shame. I can only hope for a future update.

Ne fonctionne plus depuis la mise à jour de firefox.

I use tiling windows manager and sometimes end up having 2 or 3 windows on screen. Before finding this, I used user agent overrider to switch to mobile versions of websites. But having done so much, you should enable margins.

I really like the idea; it could be handy even on my desktop Firefox. However, it largely fails in practice because it reflows the text exactly to 100% of the browser window, leaving no room for margins around the text. In the best case, the text butts up uncomfortably close to the edges of the window; in the worst, one must horizontally scroll to get the text fully in view anyway, defeating the purpose of the add-on.

It'd be a lot better if one could configure exactly what size the text is reflowed to. Being able to set it under 100% would make it possible to allow some room for the surrounding space, as well as constraining the line length to something comfortable to read on a wide-screen display (typically somewhere around 50 to 80 characters per line or so). This would make the add-on much more useful.

It would also be nice if the add-on's changes could be temporarily disabled easily (e.g., from the View > Page Style menu) without disabling all the page's own styles, in case the add-on's style rules happen to clash and create problems with a particular page's own.