: It is the final version compatible with "legacy" extensions (XUL-based), which were abandoned in subsequent releases .
This version specifically maintains compatibility with Windows XP SP2/SP3 and Windows Vista .
Select Custom instead of "Standard" installation.
Firefox version 52.9.0 ESR (Extended Support Release) is the final version of Firefox that officially supports Windows XP Windows Vista . Released on June 26, 2018 firefox version 52.9. 0 esr download
https://archive.mozilla.org/pub/firefox/releases/52.9.0esr/win32/en-US/Firefox%20Setup%2052.9.0esr.exe
Last updated: October 2025
Furthermore, 52.9.0 holds a critical, if shrinking, role in the world of legacy technology. In an age where the web is increasingly hostile to older hardware, this browser is a lifeline. It supports Windows XP and Vista—operating systems that modern browsers have long abandoned. In schools with aging computer labs, in factories running industrial machinery on Windows XP kiosks, and in the laptops of users who cannot afford modern hardware, 52.9.0 ESR serves as the last bridge to the modern web. It provides a secure (albeit outdated) tunnel to the internet where none would otherwise exist. : It is the final version compatible with
While it was the last stable, supported version, it is important to note that as of 2026, it does not receive new security patches from Mozilla. Why Download Firefox 52.9.0 ESR in 2026?
You're looking for information on downloading Firefox version 52.9.0 ESR.
Because this version is no longer featured on the main Firefox homepage, you must access Mozilla’s archives or trusted mirrors to find it. Firefox has ended support for Windows XP and Vista Firefox version 52
Within that directory, you will find:
to keep it on v52.9.0. Would you like a step-by-step for those settings? Firefox ESR 52.9.0, See All New Features, Updates and Fixes
| Problem | Solution | | :--- | :--- | | | Install an old version of uBlock Origin (legacy version 1.16.4) to block insecure scripts. | | Can't install any extensions | Go to about:config , set xpinstall.signatures.required to false . | | Certificate errors on HTTPS sites | Manually add root certificates (not for novices). Or use an SSL proxy in between. | | Pages are painfully slow | Disable WebGL, hardware acceleration, and set content.notify.interval to 500000 . |