Its ok, but what I really need is to add a rule for subdomains.
For example there is a homepage with a forum, that should have 85% to get more threads on the display and also a "showroom" with different cards etc. that should be at 150% for better reading.
Can you do that?

Problème depuis la màj 70 de firefox il semblerait que l'autozoom ne fonctionne plus. C'est bien dommage, c'était un module vraiment indispensable. Je n'ai pas trouvé d'alternatives. "zoom page we" zoome par site ou par tabulation, alors qu'il est nécessaire d'appliquer le meme zoom à tous les sites.
J'ai trouvé une alternative largement suffisante çà s'appelle Default Zoom
https://addons.mozilla.org/fr/firefox/addon/default-zoom/?src=search

Worked beautifully until Firefox 70, and the Github repo being archived doesn't make for optimism that it's being maintained any more. A shame.

Las páginas no conservan su zoom, menos todavía al aplicar la vista lectura. Tienen que pulirla, así no sirve.

Lo zoom deve sempre essere reimpostato, non tiene lo zoom su tutte le pagine! Voi che date 5 stelle, sapete cos'è lo zoom???

Really helpful on my laptop. Don't need to manually adjust the page-zoom.

Super useful ad-on, specially for people with eye sight problems. Lets you default a zoom size for all pages in firefox. No more zooming in pages individually. Very practical.... Thank you!

A+++ most relevant,easy to set up,works stably

*EDIT*
The extension always had support for such urls! All I had to do was enable regular expressions and voilla! Glad I rated 5 stars even initially!
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Super useful and straight to point extension for firefox! The only feature I would ask as a developer is to let me add rules for localhost ports so my actual testing sites dont show the custom zoom levels. Thanks!