It definitely works on Firefox 90 (the latest). Make sure you go to the GitHub page (linked in the add-on's description) and click the "Wiki" tab near the top to make sure you're setting it up right.

To the reviewers calling people idiots: if using the add on isn't intuitive its just as bad as having a non working add on. To access the activation options you need to press the ">" on the left for each short cut.

Adding some simple tutorial would have cleared up most of the bad reviews. How can you blame people for messing up when every other add on gives you an introduction? Anyway, great add on but read the github and make sure to activate the shortcut.

not working. running v89.0.6

edit: 3 years later still doesnt work

To people who are saying this doesn't work: once you are on the 'Manage Your Extensions' page, you just need to click the little gear button near the top, and then click 'manage extension shortcuts' at the bottom of the pop-up menu. The description should perhaps be updated, but the add-on works. Make sure what you want is on the list though; and this add-on can't override existing shortcuts.

In Firefox 89 there is just no option in the addon's preferences to add a shortcut. Doesn't work.

Doesn't work

Sadly, most of the reviews saying that Shortkeys isn't working for them, are prime examples of people who haven't read (or don't understand) the extension's description as well as its documentation (on GitHub).
Some of them apparently don't understand how WebExtensions work.

If you're unsure something is working as intended and/or if you're trying to get help in that respect, you should use GitHub to file a ticket and not try to pressure them with these unwarranted reviews.

The devs haven't been noticeably active in the past couple of months, so I seriously hope that this extension will continue to work as long as possible.

This extension isn't working for me.., i wanted to assign rightAlt+leftArrow to "Go Back" but it didn't work. FYI: I tried to map "alt+left" to "Go back" but this extension failed to do so.

Doesn't work. I only want to map backspace to previous page and F5 to reload a page. Neither of these works.

Best, i save my backspace again, fuck you firefox!

I will increase this rating once I have closure - what is the reason for the added permissions? Does it just need to download files, and accessing download history is associated? What files does it need to download that it can't do through updates? Or is it supposed to enable shortcuts that download or access download history? Sorry to the developer(s) if this isn't the ideal place to ask, but it didn't seem appropriate to ask as an issue on Github either. Thank you for your time, I like this extension.

I can finally disable cmd-d on the Mac! This would be 5* if I could remap it to Find.

Works exactly how it is described in the description, all the negative reviews are people who didn't actually read what this extension can do and what its limitations are.

It doesn't work.

I don't think this is the way plugin should be programmed. I understand that authors are limited to WhateverTheNameIs API, which is a ripoff from Chrome. But I do not agree with this limitations.

People say here that the extension doesn't work but won't specify what exactly doesn't work. It actually works fine. Nevertheless there's a bug: when you enable "Sync to other devices" the entry will disappear.