If you see a message about Intel-based apps or Rosetta when opening Firefox on your Mac, it means your current version of Firefox may need to be updated.

This message is displayed when using old versions of Firefox that require Rosetta or if your Mac is configured to open Firefox with Rosetta. Firefox has better performance and stability when Rosetta is not used.

You might see a message like:

“Support Ending for Intel-based Apps. This version of Firefox will not open in a future release of macOS.”

Firefox should still open for now, but this warning means that your current version may not be supported in future versions of macOS or that your Mac is configured to open Firefox with Rosetta.

Why this happens

Apple is removing support for Rosetta, a tool that allows apps built for Intel-based Macs to run on Apple silicon devices (such as M1, M2, and newer Macs). If Firefox is using Rosetta:

• macOS may show a warning
• Firefox may stop opening entirely on macOS 28
• Firefox’s performance and stability will be degraded

For more details, see Apple’s documentation.

Check if Firefox is using Rosetta

If your macOS version still supports Rosetta, you can turn it off:

1. Quit Firefox.
2. Open the Applications folder.
3. Find Firefox.
4. Right-click (or Control-click) it and select Get Info.
5. Look for Open using Rosetta.
6. If checked, uncheck it.
7. Close the window and open Firefox again.

If Firefox opens normally, the issue is fixed.

Update Firefox to the latest version

If you don’t see the Rosetta option, update to the latest version.

1. Visit the Firefox download page.
2. Download the latest version of Firefox.
3. Open the downloaded file.
4. Drag Firefox into the Applications folder.
5. Replace the existing version if prompted.
6. Open Firefox.

If you still see the message

• Make sure you are using the latest version of Firefox
• Restart your Mac after installing updates
• Check for macOS updates

If the problem continues, you can get help from Mozilla Support.

Frequently asked questions

What is Rosetta?

Rosetta is a compatibility feature from Apple that allows apps built for Intel-based Macs to run on Apple silicon devices (such as M1 and M2 Macs).

Why is Rosetta being removed?

Apple is transitioning fully to Apple silicon. Newer versions of macOS no longer support Rosetta, so apps must run natively.

Why am I seeing this warning now?

macOS is notifying you that your current version of Firefox depends on older technology that will not be supported in the future. If Firefox is already up-to-date, your Mac might be configured to launch Firefox with Rosetta.

Do I need Rosetta to use Firefox?

No. Current versions of Firefox are built to run natively on Apple silicon and do not require Rosetta.

Do I need to change anything right now?

No. Firefox will continue to work for now when run with Rosetta, but performance and stability will be degraded.

However, updating is recommended to ensure Firefox has the latest security updates. Running without Rosetta is best for Firefox performance and stability.

What happens if I keep using an old version of Firefox?

Older versions that rely on Rosetta may stop working on newer versions of macOS. Updating is recommended to ensure Firefox has the latest security updates. Running without Rosetta is best for Firefox performance and stability.

Will updating Firefox affect my data?

No. Updating Firefox does not remove your bookmarks, history or saved data.

Related articles

• Update Firefox to the latest release
• How to download and install Firefox on Mac