Apr 16, 2026 07:00:00

What were the results of installing and analyzing almost all Firefox extensions?

Software developer Jack Cab has published the results of his analysis and statistics after installing and analyzing almost all of the approximately 84,000 extensions available for Firefox.

Installing every* Firefox extension

https://jack.cab/blog/every-firefox-extension

Cab scraped the Firefox Add-ons Store and compiled a list of extensions, excluding themes and language packs. After removing unusable extensions such as those that are private or outdated, there were approximately 84,000 extensions in total. At the time of writing, a search on the add-on search page with the add-on type set to 'extensions' yielded 85,695 results.

A dataset listing and organizing Firefox extensions is available on Hugging Face.

jack5079/extensions · Datasets at Hugging Face

https://huggingface.co/datasets/jack5079/extensions

According to Cab, he was able to install 99.94% of all extensions, excluding some that were not scraped or not included in the list. Cab has also published various results from his analysis of the dataset.

First, the largest file size among all extensions is ' dmitlichess ,' which adds audio commentary from grandmasters to chess games, at 196.3MB. The smallest extension is the add-on ' Tabs-saver ' for keeping tabs, at 7518 bytes.

Furthermore, Cab named the add-on '

FalscheLaden ' as 'The 'Middle Finger Emoji Sticker' Award (the most outrageous extension that makes you want to give the middle finger).' FalscheLaden is an extension that warns users when they access domains identified as fake stores, but it requests the most permissions of all extensions, at 3695. The creator of FalscheLaden published an article explaining that the 3695 is the number of 'fake store domains,' and that the list of permissions requested on the add-on page became incredibly long because access permission had to be granted to each of these domains.

Regarding user statistics, 25.1% of extensions had more than 10 daily users, 10.6% had more than 100, 3.2% had more than 1,000, and 0.7% had more than 10,000. It was also reported that 34.3% of extensions had no daily users.

Furthermore, 76.7% of the extensions were open source. In addition, 23% of the extensions were created after Cab began writing the article, and 19% were mysterious extensions with no users, reviews, screenshots, downloads, or icons whatsoever.

While Cab's article was published on April 9, 2026, the initial version of the dataset was created in September 2025, and although it has been updated since, it may not include the latest extensions. Regarding Chrome extensions, Cab states, 'There are just too many, and there's no easy way to get them all, so it's impossible.'