For users running , downloading the latest version of Mozilla Firefox directly from the main website will not work. Modern versions of Mozilla Firefox require macOS 10.15 (Catalina) or later.
Security and compatibility tips
For convenient access, you may want to add Firefox to your Mac’s Dock. To do this, open your Applications folder, locate the Firefox application icon, and drag it to the Dock. The Dock icon will remain there for future use, allowing you to launch Firefox with a single click.
While this version allows you to browse the web, it is no longer receiving security patches. For better security, consider upgrading your macOS if your hardware supports it (e.g., to macOS 10.15 Catalina). Where to Download firefox download for mac 10105 upd
Do not install any offered update to Firefox 91+ or 100+. It will become unusable on 10.10.5.
Tell you how to (if supported). Recommend specific privacy settings for an older Firefox.
It looks like you’re trying to find a . For users running , downloading the latest version
: You can download this specific legacy version directly from the Mozilla FTP Archive. How to Install
A: Yes. Firefox is configured by default to automatically download and install updates. You will be prompted to restart the browser when an update is ready to be applied.
As of 2026, finding a "Firefox download for Mac 10.10.5 upd" (update) means finding the last supported version, as Mozilla has moved on to higher macOS requirements. This guide will walk you through the best, secure way to get Firefox running on your Yosemite machine. Why You Need a Specific Firefox Version for Yosemite To do this, open your Applications folder, locate
Mozilla regularly updates Firefox to include new web standards, security protocols, and performance optimizations. However, modern software requires modern operating system foundations.
A: Yes. Firefox is fully optimized for both Intel-based Macs and Apple silicon (M1, M2, M3, and later) Macs running macOS 10.15 or newer. The browser automatically detects your processor type and delivers the appropriate version.
Because Firefox 78 ESR reached its final security cycle in October 2021, you must alter the default browser engine properties to maintain functionality and preserve resources on older hardware. Terminate Automated Update Loops
(Re-enable after install: sudo spctl --master-enable )
Open Firefox from your Applications folder. You may see a security warning since it is an older version; click to proceed.