You will see a long list of folders (e.g., 3.0, 3.5, 3.6, 4.0...).
The main add-ons site (addons.mozilla.org) no longer serves 3.6-compatible plugins. However, you can find XPI files for Firebug 1.6, Adblock Plus 1.3, or NoScript 2.0 via the Internet Archive’s Wayback Machine.
Some software archives like oldapps.com mirror Mozilla's FTP. Use with caution. Compare the file size and hash against Mozilla’s official list.
Do not enter passwords, credit cards, or personal data. Firefox 3.6 is over a decade old and has more unpatched security holes than Swiss cheese. Use only in a sandbox, virtual machine, or offline environment.
Downloading a legacy version of a browser like Mozilla Firefox 3.6
is possible through official archives, though it is generally discouraged for daily browsing due to severe security risks. Mozilla Support Where to Download Firefox 3.6
The safest way to acquire old versions is directly from Mozilla's official servers rather than third-party mirror sites. Mozilla Support Official Mozilla FTP Archive : The primary source for every release is the Mozilla FTP Directory Navigate to the folder (or specific minor versions like Select your operating system (e.g., linux-i686 Choose your language folder (e.g., for English). Download the (Windows), (Linux) installer file. Third-Party Legacy Sites : Sites like OldVersion.com
also host these files, though official servers are preferred for integrity. Critical Safety Considerations Using a browser from 2010 in 2026 presents major hazards: Download Mozilla Firefox 3.6 - OldVersion.com Official Website: http://www.mozilla.com/firefox. OldVersion download old version of mozilla firefox 3.6
Technical Report: Acquisition of Legacy Mozilla Firefox 3.6 This report outlines the procedure for downloading and installing Mozilla Firefox 3.6 , an end-of-life version originally released in January 2010 www.mozilla.org 1. Official Download Source
The safest and most reliable way to obtain legacy versions is through the official Mozilla FTP Archive
. Use the following direct directory paths to locate the specific installer for your operating system: Version 3.6.28 (Final Release of the 3.6 Branch): Directory Listing for v3.6.28 Windows (US English): Windows Installer (win32/en-US) Mac Disk Image (mac/en-US) Linux Archive (linux-i686/en-US) mozilla.org 2. System Compatibility & Requirements
Firefox 3.6 was designed for legacy hardware and operating systems. Mozilla Support Operating Systems:
Supports XP SP2, Vista, and Windows 7 (32-bit and 64-bit versions run the 32-bit build).
Compatible with Mac OS X 10.4, 10.5, and 10.6. This is the last major version to support PowerPC (PPC) Requires a minimum of 512 MB of RAM and a Pentium 4 or newer processor. 3. Critical Security & Performance Risks Using a browser from 2010 in 2026 presents severe risks: Unpatched Vulnerabilities:
This version contains hundreds of known "Critical" and "High" security flaws that will never be patched. Modern Web Incompatibility: You will see a long list of folders (e
Most modern websites (including YouTube, Outlook, and banking sites) will not render correctly or may fail to load due to outdated CSS, JavaScript, and security certificates. Profile Corruption:
Installing an older version over a modern Firefox profile can corrupt your bookmarks
, history, and saved passwords. It is strongly recommended to use a new Firefox profile for this version. Mozilla Support 4. Alternative for Compatibility Firefox 36.0 System Requirements
You can download Mozilla Firefox 3.6 directly from official Mozilla archives or reputable third-party repositories. Because this version is over a decade old, it lacks modern security updates and may not display many current websites correctly. Official Mozilla Archives (Recommended)
Mozilla maintains a public directory of every release. This is the safest way to ensure you are getting an untampered file.
Direct Archive Link: Browse the Index of /pub/firefox/releases/3.6/ on the official Mozilla FTP.
Specific Sub-Versions: If you need the final update of this branch, visit the 3.6.28 directory . Third-Party Repositories Do not enter passwords, credit cards, or personal data
If the official archive is difficult to navigate, these community sites offer direct mirrors:
OldVersion.com: This site specializes in preserving legacy software. You can find Firefox 3.6.x versions for various Windows editions .
Uptodown: Offers a version history for Firefox, including portable versions that don't require a full installation . Installation Tips
Disable Auto-Updates: Immediately after installing, go to Tools > Options > Advanced > Update and select "Never check for updates" to prevent it from automatically jumping to the latest version.
Custom Install Directory: If you already have a modern version of Firefox, choose a "Custom" installation path (e.g., C:\Program Files\Firefox3) to avoid overwriting your current browser .
Security Warning: Use this version only for testing or legacy compatibility (like old web-based hardware interfaces). Avoid logging into sensitive accounts like banking or email . Install an older version of Firefox - Mozilla Support