Buggy. Support is not helpful. The source code of version 3 is not open, so it's not GNU.

Will use Stylus: https://addons.mozilla.org/en-US/firefox/addon/styl-us/

It won't work, and it keeps taking me to chrome repair when i am using firefox.

Useless with Quantum Firefox

Another excellent extension made totally worthless by quantum firefox upgrade.

good grief! talk about how to take a simple plugin and absolutely destroy it. i used this all the time. now? it's a !@#$ expedition to firgure out how to write new styles for a page. how the hell do you screw up something so simple as 'write new rule' from the menu popup? godawful transition to the new version. utterly useless to me now.

new version Stylish for Firefox 57+ is HORRIBLE... similliar like same Firefox 57

Before webextensions, Stylish for Firefox was awesome. Sytylish for Chrome always sucked compared to Firefox's Stylish and now, since webextensions, Firefox Stylish is just as bad as Chrome Stylish. Webextensions is KILLING Firefox! The so-called "speed increase" isn't there and does NOT justify the GUTTING of Firefox extension functionality!

Firefox Stylish can no longer do real-time CSS updating (must reload/refresh web page EACH and EVERY time!), editing in a window (vs. tab only), and its import feature can only handle so many subsections before it just stops adding them and you must add them manually). Those are my biggest gripes about the webextensions Firefox Stylish, I can no longer continue to use it or Firefox 57+ until this functionality is restored and Mozilla wakes the hell up and realizes webextensions are stupid.

Hello! Please, I am having problems to enjoy this extension, already installed, in my Firefox, from a few days to here. I'm with Mozilla Firefox, in this version: (57-0-1-64-bit).
In the upper corner of my browser, the Stylish icon, the following message appears: "An error has occurred using the Stylish database. Would you like to visit a web page with possible solutions?"
Please, to the engineers and technicians of "Stylish", I love this extension, but I'm sad that it stopped working. Can you instruct me so that I can solve this mistake?
Right now, grateful.

Используйте старые версии от 2016 года!!!
Все работает и восстановились старые стили а новый stylish это какой то тихий ужас
Тормозит браузер не сохраняет стили и глючит!

I simply want to change the colour of 'visited links' to RED so that I can easily see which results I have clicked on. A friend showed me a Google result that mentioned this add on being able to help me, but I don't know where to start. I'm 74 years of age and computing is not my strong area. I used to have this ability on my computer, which I seem to have lost since I downloaded the very latest Firefox. I have lost contact with the person who installed it for me.

The new version makes it that much harder to design an idea, make changes, and test them in real time without having to actually reload the webpage multiple times to see what you're doing. Older versions, prior to this Web Extensions rollout, were fantastic for this, allowing me to minimize my impact on server resources while making webpages more accessible to my visual needs.

Needs to be fixed for FireFox 57

Doesnt work on Firefox properly anymore!!!! Needs to be fixed!!!!

Stylish was a great add-on, but become completely broken after update. Styles are gone, creating new styles not working. Best update ever!

Sigh. I've tried and tried and tried, and I CANNOT add any new styles with your new "improved" version for firefox, nor can I import my old ones.

As another use posted here.."It also will not save my styles when I try to manually import them--the save button does nothing at all. I can't even install new styles from userstyles.org--it just takes me to the addon installation ..."

Reading all of these comments, is just pathetic. Thanks for saving my old styles, unfortunately, you provide no way to add them, either by import or manually adding them as new.

terrible.

My two pages of browser chrome customizations are gone after the latest update.

Look, I understand it's no longer possible in Firefox 57, but if you hadn't just erased them, I could have placed them into userChrome.css manually...

First time user, trying to add this after Firefox upgrade to 57.0. Install repeatedly fails with Database error. Online help only references Chrome, not Firefox, and Chrome help does not contain enough context to find correlated issues in Firefox.
Gave it up, installed Stylus Beta instead, which installed and worked perfectly the first time. Clearly this was not adequately tested.
See you, bye ...