While it might seem counterintuitive to seek out an older version of a browser in an era of constant updates, many users have valid reasons for doing so—ranging from hardware compatibility to specialized technical testing. Why People Use Old Versions of Firefox
After installing your old Firefox:
Look for .
Download Sandboxie Plus, run old Firefox inside a sandbox. firefox old version
The safest way to get an older build is directly from the source to avoid malware bundled in third-party installers. While it might seem counterintuitive to seek out