Firefox’s list of the most popular and innovative add-on browser extensions of 2021 was dominated by ad blockers, a clear sign that users value their privacy without being tracked.

To determine which add-ons are most popular, Firefox calculates its average daily users (ADU) throughout the year.

In 2021, Adblock Plus topped the list with an average of 6,134,232 daily users. Second on the list was uBlock Origin, with an average of 5,011,974 daily users.

Others to make the list include Mozilla’s Facebook Container, which had an average of 1,740,395 daily users, and the tracking add-on Ghostery, which had an average of 1,167,938 daily users.

Firefox also revealed the data that represent the total number of visits addons.mozilla.org had in 2021.

The five countries from which the visitors came were China, the United States, Germany, France and Russia. Firefox also stated that one-third of all users had already installed an add-on and that in 2021 alone, there were a total of 127 million Firefox add-on installations.

Other extensions that are also mentioned are tab organizer add-ons like Sidebery and Tab Stash. Website design tools like Stylebot and automaticDark have also been mentioned.