Firefox 78 Portable Updated Download May 2026

Released in October 2021.The ESR version contains over a year's worth of additional security backports and bug fixes that the standard version lacks, making it the superior choice for a legacy download. If you'd like, I can help you with: Finding the direct link for your specific operating system

It is the last major version for Windows XP and Windows Vista users (via the ESR branch).

Step-by-step instructions on so it stays on version 78 Troubleshooting compatibility issues with modern websites firefox 78 portable download

The Extended Support Release (ESR) is the most stable iteration of version 78. 2. Mozilla FTP Archive

This is a self-extracting portable archive. Run the Installer: It will ask for a "Destination Folder." Released in October 2021

Do not use it for banking or sensitive logins.

It supports older macOS versions (10.9, 10.10, and 10.11) that newer Firefox versions cannot run on. It supports older macOS versions (10

The most reliable source for the "Portable Edition" format is the PortableApps.com SourceForge archive. Firefox Portable 78.15.0 ESR