This is perfect for youtube full resolution in browser under vertical tabs mode, as it is like some other websites that does not fit properly for the new feature.

Zoom Page WE knows how to make good software. But they do NOT know how to provide decent instructions for them.

For instance their instructions say this:
"After installation of Zoom Page WE, there will be a new icon on the main toolbar with a blue badge showing the current zoom level."

That is NOT true. There was no blue icon on the toolbar (and they should have shown a picture of the icon to let us know what it looks like).

Here is how to make that icon appear in Firefox version of Zoom Page WE:

Click on the Firefox Extension icon which is on the Firefox Toolbar. Right click on Zoom Page WE and choose "pin to toolbar"

Dommage mais ce développeur a abandonné ce module qui était l'un des meilleurs, autant celui pour Firefox que celui pour les navigateurs Chrome/Edge. Il commence à disfonctionner même sur Firefox maintenant vu qu'il fonctionnait déjà assez mal sur Edge.

I am totally enthusiastic about this extension because it allows you to enlarge the font on a homepage on a per-site basis. I have been looking for this for a long time. I was always annoyed that there was no extension for Firefox like Zoom Text only for Google Chrome.

works perfectly

Works for me.

Most important add-on/extension ever, anywhere. I avoid all browsers that can't do exactly what this lets Firefox do.