Once you’ve completed the firefox download for mac 10105 upd, speed up your legacy Mac:
| Step | Action |
|------|--------|
| 1 | Open archive.mozilla.org/pub/firefox/releases/ |
| 2 | Click 78.15.0esr/ |
| 3 | Click mac/ |
| 4 | Click your language folder (e.g., en-US) |
| 5 | Download Firefox 78.15.0esr.dmg |
| 6 | Install, then disable automatic updates |
| 7 | Enjoy the latest possible update for Mac 10.10.5 |
Mozilla no longer links old versions directly. Use the official archive:
🔗 Mozilla FTP directory (safe, official):
https://ftp.mozilla.org/pub/firefox/releases/78.15.0esr/mac/
Steps:
✅ Checksum verification (optional but recommended): firefox download for mac 10105 upd
Since this is an older build, macOS might block it due to an expired gatekeeper ticket. If you see the warning “Firefox can’t be opened because it was not downloaded from the App Store”:
Running Firefox 78.15 in 2026 means no new security patches for Firefox-specific vulnerabilities (CVEs after Nov 2021 are unpatched). However:
Firefox download for mac 10105 upd gives you the best available browser, but not a perfect shield.
Solution: Many extensions still work on Firefox 78. For uBlock Origin, install from legacy collection – choose a version from 2021.
| Setting | Action | |---------|--------| | Update checks | Turn off (otherwise it will nag about unsupported newer versions) | | Telemetry | Uncheck “Allow Firefox to send technical data” | | Hardware acceleration | May cause glitches – try disabling if UI lags | | Add-ons | Use uBlock Origin legacy version (last working for FF 78) | Once you’ve completed the firefox download for mac
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.
It looks like you’re trying to find a Firefox download for Mac OS X 10.10.5 (Yosemite). | Step | Action | |------|--------| | 1 | Open archive
However, the latest versions of Firefox no longer support OS X 10.10.5. Mozilla ended support for 10.10, 10.11, and 10.12 after Firefox 78 (ESR) and Firefox 79+.
Here’s what you can do:
Or download from Mozilla’s official “Firefox for older Macs” page:
Note: Using Firefox 78 ESR means no new features, and security updates ended in 2021. For better security, consider updating macOS (if your Mac supports it) or switching to a lightweight browser like Pale Moon or Arctic Fox (community-maintained for older macOS).
If you meant macOS 10.15 (Catalina) instead of 10.10.5, let me know and I’ll give you the latest compatible Firefox link.
It is important to note that Firefox no longer supports macOS 10.10.5. The current version of Firefox requires macOS 10.15 (Catalina) or newer.
However, you can still install a working version of Firefox on your Mac, but you must install an older version (Firefox 78.15.0 ESR).