Firefox Version 52.9. 0 Esr Download |verified| May 2026

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

Choose the installer based on your operating system and preferred language: Windows (32-bit): English (US) All Languages Windows (64-bit): English (US) All Languages Mac (macOS): English (US) All Languages Linux (64-bit): English (US) All Languages 🛠️ Installation Guide firefox version 52.9. 0 esr download

From there, navigate to:

To ensure a successful installation, especially if you are downgrading from a newer version, follow these steps: 1. Backup Your Data Back up your bookmarks, passwords, and history On Windows, profiles are located at: %APPDATA%\Mozilla\Firefox\Profiles\ Super User 2. Prevent Automatic Updates Firefox version 52

Running ancient enterprise apps – Internal dashboards or intranet sites that rely on NPAPI plugins (Java, Silverlight, Adobe Flash – all now deprecated and insecure).
Add-on preservation – Users who depend on irreplaceable legacy extensions that never got ported to WebExtensions.
Old hardware – Windows XP or Vista machines that cannot run newer browsers (though this is extremely dangerous).
Software testing – Developers debugging legacy web applications.
Retro computing – Enthusiasts building period-correct Windows XP environments.

If you still need to proceed, follow these steps to obtain the legitimate, unaltered installer: Running ancient enterprise apps – Internal dashboards or

Legacy Add-on Support

: It is the final version compatible with "legacy" extensions (XUL-based), which were abandoned in subsequent releases .