There are several extensions that block the mining on sites that uses it and in no particular order are many examples: https://addons.mozilla.org/firefox/addon/nominer-block-coin-miners/ https://addons.mozilla.org/firefox/addon/no-coin/ https://addons.mozilla.org/firefox/addon/miningblocker/ https://addons.mozilla.org/firefox/addon/themineblock/ https://addons.mozilla.org/firefox/addon/nominers/ https://addons.mozilla.org/firefox/addon/coinblock/ https://addons.mozilla.org/firefox/addon/coin-mining-blocker/ https://addons.mozilla.org/firefox/addon/notmining-org/ https://addons.mozilla.org/firefox/addon/no-miner/ https://addons.mozilla.org/firefox/addon/minerblock-origin/ For extensions like uBlock Origin and Adblock for Firefox. https://github.com/hoshsadiq/adblock-nocoin-list/

Extensions being hosted on a.m.o are reviewed especially if by a new author. https://developer.mozilla.org/Add-ons/AMO/Policy/Reviews https://addons.mozilla.org/en-US/faq Extensions that turn out to be questionable in some way may likely be added to https://addons.mozilla.org/blocked/ though many of these that were on a.m.o were not approved or public to start with. You can look at the reviews and rating and see if you find one that suits your needs.