If you are looking for the most secure version of Firefox today, you should download the (currently in the 115+ or 128+ range) to ensure you have the most up-to-date protection. If you'd like, I can help you: Find the latest secure ESR version for your OS Set up Group Policy for an office deployment Troubleshoot compatibility issues with legacy web apps
Mozilla maintains an official archive of every version ever released. You can find it under the "releases" directory on the Mozilla server. firefox esr 42 download
Enhanced tools for developers to build and debug web apps directly within the browser. How to Download Firefox ESR 42 If you are looking for the most secure
Download the .exe , .dmg , or .tar.bz2 file and follow the prompts. Security Warning for Legacy Versions Enhanced tools for developers to build and debug
This version introduced enhanced privacy by blocking web elements that could track your activity across multiple sites.