Download the final compatible installer package directly from the Mozilla CDN Release Archive. Navigate to the mac/ subdirectory.
Many extensions still work on Firefox 78. For uBlock Origin, install from legacy collection – choose a version from 2021.
Using an outdated browser on an unsupported operating system poses . Because Firefox 78.15.0esr no longer receives security updates, your data may be more vulnerable to modern web threats.
If you are trying to keep an older Mac functional, this guide outlines the direct download details, installation steps, and alternative solutions to ensure a safe browsing experience. Technical Specifications & Support Limits firefox download for mac 10105 upd
If you try to install a newer Firefox (version 100+), the installer will fail with an error: “You cannot use this version of Firefox with this version of macOS.”
A: Yes – Firefox Sync works on 78 ESR (sign in with a Mozilla account).
Because you are on the ESR branch, Firefox will try to update to a newer ESR (like 91 or 102), which will break compatibility. For uBlock Origin, install from legacy collection –
Do not run Firefox directly from the .dmg file, and do not drag the Firefox icon directly onto your desktop to install it. Doing so could lead to issues such as lost data, missing settings, or instability. Always drag the Firefox icon to the Applications folder to ensure proper installation.
Download the file: Firefox 78.15.0esr.dmg (size ~85 MB).
Newer versions of Firefox (released after version 79.0) require macOS 10.12 Sierra or higher, meaning modern updates will not install on a Mac running Yosemite 10.10.5. If you are trying to keep an older
When Apple stopped updating OS X 10.10 Yosemite, third-party software support eventually followed. For users searching for the definitive download for , understanding the cutoff timeline is critical: Final Compatible Release : Firefox 78.15.0esr Release Channel : Extended Support Release (ESR) End of Life (EOL) Date : October 5, 2021
A finder prompt window will open displaying the Firefox logo next to your local Applications directory shortcut.
Click on the file to begin the download. Step 2: Install the Application
Download the final compatible installer package directly from the Mozilla CDN Release Archive. Navigate to the mac/ subdirectory.
Many extensions still work on Firefox 78. For uBlock Origin, install from legacy collection – choose a version from 2021.
Using an outdated browser on an unsupported operating system poses . Because Firefox 78.15.0esr no longer receives security updates, your data may be more vulnerable to modern web threats.
If you are trying to keep an older Mac functional, this guide outlines the direct download details, installation steps, and alternative solutions to ensure a safe browsing experience. Technical Specifications & Support Limits
If you try to install a newer Firefox (version 100+), the installer will fail with an error: “You cannot use this version of Firefox with this version of macOS.”
A: Yes – Firefox Sync works on 78 ESR (sign in with a Mozilla account).
Because you are on the ESR branch, Firefox will try to update to a newer ESR (like 91 or 102), which will break compatibility.
Do not run Firefox directly from the .dmg file, and do not drag the Firefox icon directly onto your desktop to install it. Doing so could lead to issues such as lost data, missing settings, or instability. Always drag the Firefox icon to the Applications folder to ensure proper installation.
Download the file: Firefox 78.15.0esr.dmg (size ~85 MB).
Newer versions of Firefox (released after version 79.0) require macOS 10.12 Sierra or higher, meaning modern updates will not install on a Mac running Yosemite 10.10.5.
When Apple stopped updating OS X 10.10 Yosemite, third-party software support eventually followed. For users searching for the definitive download for , understanding the cutoff timeline is critical: Final Compatible Release : Firefox 78.15.0esr Release Channel : Extended Support Release (ESR) End of Life (EOL) Date : October 5, 2021
A finder prompt window will open displaying the Firefox logo next to your local Applications directory shortcut.
Click on the file to begin the download. Step 2: Install the Application