Firefox Preview is an early version of Mozilla’s new browser for Android. Firefox Preview has been rebuilt from the ground up using GeckoView, Mozilla’s new mobile browser engine, for a faster, sleeker experience. See Jaký je rozdíl mezi Firefoxem Preview a Firefoxem pro Android? for more information.

Extension compatibility for Firefox Preview

We are currently building support for an initial selection of Recommended Extensions for Firefox Preview. These extensions are expected to be officially supported for Firefox Preview during the first half of 2020.

While some members of the community have discovered that some extensions (Recommended and non-Recommended) inadvertently work in Firefox Preview, we do not recommend attempting to install them until they are officially supported as other issues may arise.

Theme compatibility for Firefox Preview

Due to Firefox Preview's minimal user interface (UI), only a limited number of pre-installed themes will work. See Jak změnit motiv vzhledu ve Firefoxu Preview to learn how to select one of those themes.