Firefox Download For Mac 10105 Upd May 2026

⚠️ Recommendation: If possible, upgrade macOS or use a lightweight modern browser like Chromium Legacy or Waterfox Classic.

Summary

Important note

Download & install steps

Security and compatibility tips

If you want, I can draft a short webpage blurb, email, or step-by-step checklist tailored for end users or IT staff.

Keeping Yosemite Alive: How to Download Firefox for Mac 10.10.5

If you’re still rocking a Mac with OS X Yosemite (10.10.5), you know the struggle. Modern websites are heavy, and Safari 8 feels like it's trying to run a marathon in flip-flops. You need a browser that still respects your hardware while letting you actually check your email. firefox download for mac 10105 upd

Enter Firefox. While Mozilla has officially moved on to newer versions of macOS, you can still get a functional, stable version of Firefox for your Yosemite machine. Here is everything you need to know to get back online. The Best Version for Yosemite: Firefox 78 ESR

For users on Mac OS X 10.9, 10.10, and 10.11, the "end of the road" was Firefox version 78 Extended Support Release (ESR).

Why this version? It was the last major release to officially support Yosemite.

Is it safe? It received its final security update (version 78.15.0esr) on October 5, 2021. While it's more secure than the outdated version of Safari that comes with Yosemite, it no longer receives active patches. Step-by-Step: How to Download and Install

Since the main Firefox Download Page will likely try to give you the newest version (which won't open on your Mac), you need to grab the specific legacy installer.

Get the Installer: Navigate to the Mozilla Support Page for Legacy Mac Users or search for the Firefox 78.15.0esr dmg directly.

Open the DMG: Once the download finishes, double-click the Firefox 78.15.0esr.dmg file. ⚠️ Recommendation : If possible, upgrade macOS or

Install: Drag the Firefox icon into your Applications folder.

Launch: Open your Applications folder and double-click Firefox. You might see a warning that it was "downloaded from the internet"—just click Open. Pro Tips for Older Macs Browser Suggestions for Old Mac Laptop Yosemite 10.10.5

Download Firefox for Mac OS X 10.10.5 (Yosemite)

If you're using Mac OS X version 10.10.5 (Yosemite), you can still run an older but stable version of Firefox that is compatible with your system.

Important Note:
The latest versions of Firefox no longer support OS X 10.10.5. The last compatible release is Firefox 78 ESR (Extended Support Release), which includes security updates until November 2021.

Steps to Download Firefox 78 ESR for OS X 10.10.5:

Direct download link (official Mozilla source):
https://ftp.mozilla.org/pub/firefox/releases/78.15.0esr/mac/en-US/ Summary

Note: After installation, it's recommended to avoid updating to newer versions, as they will not work on OS X 10.10.5.

I notice you mentioned “Mac 10105” — I believe you may be referring to macOS 10.10.5 (Yosemite) or possibly 10.10.5 as a version number.

If that’s the case, here’s a full feature guide on downloading and running Firefox on macOS 10.10.5, including compatibility, risks, and step-by-step instructions.

If you find that Firefox 78 is sluggish or still incompatible with websites you need, consider these legacy browsers:

Searching for “firefox download for mac 10105 upd” is a smart move if you’re keeping a classic Mac alive. The final, secure, and usable version is Firefox 78.15.0esr. While you won’t receive modern updates beyond that, following this guide ensures you have the most functional browser available for macOS Yosemite 10.10.5.

Next steps after download:

Bookmark this article – and share it with others still running the legendary OS X Yosemite.

Last verified for compatibility: May 2026. Mozilla may remove older builds from archives, but the paths mentioned remain valid as of this writing. For commentary on legacy Mac browsers, check the r/firefox and r/macos subreddits.