How to Enable Developer Installation of Local Add-ons on Firefox for Android

1. Enable developer mode#

Firefox has a built-in debug menu, hidden by default. Activate it as follows:

设置 → 关于 Firefox → tap the Firefox logo five times in a row

A toast appears at the bottom: 已启用调试菜单

Go back to 设置, and a 从文件安装插件 option appears under 高级选项

2. Install a local add-on#

1. On the add-on page of the Firefox add-on store, click Download file and download the .xpi file to your phone

The Add button can’t be clicked here, so installing locally is the only option

2. Activate the debug menu described above

3. 设置 → 从文件安装插件 → select the downloaded .xpi

4. Done

Only signed add-ons are supported. Official xpi files downloaded from AMO are all signed. Unsigned add-ons from third-party sources may be rejected

Firefox Android restricts add-on compatibility, on the grounds that mobile APIs and desktop APIs aren’t exactly the same, and some add-ons crash on phones. Add-ons like Wappalyzer that read page information are actually perfectly fine; the official side simply hasn’t marked them as compatible

After a forced install, Wappalyzer displays completely normally on Firefox Android