When comparing Firefox Nightly vs GNU IceCat, the Slant community recommends GNU IceCat for most people. In the question“What are the best desktop web browsers?” GNU IceCat is ranked 5th while Firefox Nightly is ranked 24th.
Ranked in these QuestionsQuestion Ranking
Pro Blazing fast
Short load times. Quick tab switching. Fast rendering.
Pro Access to new features
Nightly comes after beta which means you get access to more features.
Pro Extra security and privacy features
Pro All the benefits of Firefox, but with 100% free software
Pro Protects your freedom, certified free by the FSF
Blocks privacy trackers.
Blocks unwanted JS code.
Pro Https-Everywhere by default
Pro Made by idealists
It is part of the GNU Project.
Con Buggy; performance issues and crashes
Because you're accessing new Firefox features, bugs and crashing comes. Firefox Nightly is meant for developers and it's for PCs that have low chance of getting attacked. If Firefox is for you, go for the normal one or beta at least. If you use Nightly, checking updates regularly is recommended.
Con Not intended for general use
This browser was made for testing purposes for future versions of Firefox, and it can easily crash. Most people should use the stable release of Firefox.
Con Mainly just an old Firefox
It is mainly a renamend older version of Firefox that comes preinstalled with some extensions.
Con Dependent on Mozilla
Since IceCat is based off Firefox, it's dependent on all of Mozilla's decisions.
Con Can't install some Firefox themes/addons
"Installation aborted because the addon appears to be corrupt".
Con Too much bloat
The browser comes with 15 addons installed by default, most of which are useless or ruin one's browsing experience.