Finding and Downloading Older Versions of Firefox for Testing

Finding and Downloading Older Versions of Firefox for Testing

3 July 2024 Stephan Petzl Leave a comment QA

For software testers, having access to specific versions of web browsers is crucial for ensuring compatibility and identifying issues. Firefox, being one of the most popular browsers, often requires testing on various versions and language builds. This guide will help you locate and download older versions of Firefox efficiently.

Official Mozilla FTP Directory

One of the most reliable sources for downloading older versions of Firefox is the official Mozilla FTP directory. This directory is well-organized and offers several advantages:

  • Official: The source is maintained by Mozilla, ensuring the files are legitimate and safe.
  • Organized per OS/arch: You can find versions tailored for different operating systems and architectures.
  • Organized per Version: The directory includes Beta, Aurora, and Nightly builds, along with stable releases.
  • Organized per Language: You can download specific language builds, which is particularly useful for localization testing.

However, keep in mind that the FTP directory has limited mirrors. For extensive downloading or linking, consider using the official Releases server to avoid putting excessive load on the FTP directory.

Alternative Sources

While the official FTP directory is highly recommended, there are other sources you can consider:

  • OldApps: This site provides a variety of older browser versions, including Firefox. However, for Firefox-specific needs, the official FTP site remains the best option.
  • BrowserStack: This service allows you to run almost any browser on any operating system, making it a versatile tool for testing. You can also run Selenium tests on BrowserStack, which can be particularly useful for automated testing scenarios.
  • Utilu: Utilu offers old versions of Firefox and Internet Explorer, including the latest nightly and beta builds. The advantage of Utilu is that each version is standalone, eliminating the need for installation and reinstallation.


Accessing older versions of Firefox is essential for comprehensive browser testing. The official Mozilla FTP directory is the most reliable source, but alternatives like OldApps, BrowserStack, and Utilu can also be beneficial depending on your specific needs.

For those looking to streamline their testing process further, consider using Repeato, a no-code test automation tool for iOS and Android. Repeato allows you to create, run, and maintain automated tests for your apps quickly and efficiently. Its computer vision and AI-based approach make it particularly fast to edit and run tests, ensuring your quality assurance processes are both effective and easy to manage.

For more information, visit our documentation page or check out our blog for additional resources and guides.

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