Full offline installers for all languages of Firefox developer are now available from ‘download developer edition in your language’ page. We all know Mozilla offers stub installer for their Firefox browser in release, beta, Developer edition and Nightly versions. We can still able to download full installer for any Firefox channel by selecting ‘Systems & Languages’ from the channel page.
How to Download Firefox Developer edition offline installer
1. Visit https://www.mozilla.org/en-US/firefox/developer/all/
2. Depending on the Operating System (Windows, Linux or Mac) and version (32 or 64-bit), download the appropriate file to your computer.
3. Run it to install latest Firefox developer version offline on your computer.
READ: Firefox Stub Installer gets Resume Support
Firefox 55: Mozilla to Ship Streamlined Stub Installer for Windows
Thanks!