Compare software

GNU IceCat vs Mercury: catalog facts
GNU IceCat	Mercury
Free Free software from the GNU Project with no paid tier.	Free Free and open source.
Linux	Windows, macOS, Linux
Contains only free software, with no nonfree add-on recommendations LibreJS blocks nonfree JavaScript	Compiler-optimized Firefox builds Privacy patches drawn from LibreWolf, Waterfox and IceCat
Blocking JavaScript breaks many modern sites until you allow scripts Builds are distributed from a third-party download page	Maintained by a single developer Updates can trail official Firefox releases
Downloadable app	Downloadable app
Open source	Open source
License not stated	License: MPL-2.0
No account needed	No account needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Checked September 23, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.