I want to start with 100 % whitelistening and then blacklist (very few) sites I want.

NEW COMMENT (2023-09-22) = DEFINITELY UNINSTALLING AND WILL NEVER INSTALL THIS AGAIN... You spend weeks (months?) adding rules just to see the addon bug... Company response? SORRY... OUR ADDON IS BUGGED AND THIS IS BY DESIGN... Changing to other ad block that works...

NOVO EDIT EM 2022-12-10:
Been using Firefox addon for some time and no problems... Until yesterday...But it is impossible to use it any longerMy browser started to have slowdowns, pages didnt load, addons couldnt be configured...After a few hours of trying, found all problems are caused by AdGuard...If I enable, cant do anything... If I disable, all is fine...Will switch back to AdBlock...When you have a solution I might return...


EDIT = SEM SAVE AUTOMATICO DAS CONFIGURACOES... Se precisar reinstalar = FERROU... Mesmo tendo a opcao de salvar localmente, se der pau no HD = PERDEU TUDO... E ainda, QUEM SE LEMBRA DE SALVAR AS REGRAS TODA SEMANA? NOTA ZERO...
Usava o Adblock Plus, mas varios sites estavam detectando o uso e mostravam avisos pedindo para desativar a extensao. Mudei para o AdGuard e nunca mais recebi este aviso. Este addon eh muito melhor, mais leve, mais rapido e bate o Adblock em tudo. Recomendo demais que voce troque (ou pelo menos TESTE) o AdGuard...
I used Adblock Plus, but many sites detected the addon and showed a message ate the bottom asking me to disable the extension. Changed to AdGuard and never saw the message again. This addon is faster, lighter, much better than Adblock. I do recomend you to use AdGuard (or ate lest, TRY IT)... Much much better than AB...

Kurz und Knapp, Facebook ballert immer noch Werbung rein. Deinstallation kommt.

Youtube other google products, homedepot, some weather sites and all kinds of sites over night just no longer load and/or respond now.
Can't even submit issue b/c that's not working properly now

Long days ago it was the best free Ad-Blocker.... Now it dont even blocks youtube ads and u get ads even in the middle of a video clip u are listenig... I advice everyone to look for a better alternative now!

Not blocking anything on firefox on my laptop at the moment.

Поначалу это расширение работало очень хорошо. Через некоторое время начались незначительные пропуски рекламного мусора, но сначала надеялся, что случайные. Спустя 3-4 месяца число рекламных довесков стало увеличиваться, несмотря на правильно (выборочно) включенные и регулярно обновляющиеся фильтры. Решил снести его и поставил uBlock Origin. Уже давно никаких косяков и ни единой проблемы:)

Does not work on firefox 72 beta

Doesn't block ads anymore for Firefore Dev Edition.