When you change the extension for a file in macOS, you’re normally treated with a warning. And if you’re someone who changes file extensions a lot, then you may soon get annoyed by the warning. Luckily, there’s an easy way to turn off the change file extension warning in Mac.

There are actually two ways to go about this, and we’ve detailed them below. As a reminder, you should only disable this feature if you know what you’re doing. Changing a file’s extension could corrupt the file and you may not be able to undo the changes. Let’s take a look at the two methods below.

Related: find out how to display file extensions on Mac.

Disable change file extension warning via Finder

The easiest way to turn off the warning for file extension changes on macOS is via the Finder. It’s simple, and pretty quick. Here’s what you need to do.

  1. Launch Finder and then navigate to the top Menu bar.
  2. Click on Finder > Preferences and select the Advanced tab.
  3. You should see an option called ‘Show warning before changing an extension‘. Uncheck this option.


Now close the dialog box and you will no longer see the warning that you’d normally get when making changes to a file extension. Remember, changing the extension may not work with all files. This is useful for those users who deal with plenty of files.

Turn off file extension changes warnings using Terminal

Here’s the second method that you can use to disable the warning you get when changing file extensions. This method involves using the Mac’s Terminal. Here’s how you do it.

  1. Launch the Terminal on your Mac via the Launchpad or the Applications folder.
  2. Type in the following command – defaults write com.apple.finder FXEnableExtensionChangeWarning -bool false
  3. Now enter killall Finder to relaunch the Finder.
  4. To re-enable the warning, you’ll need to enter the following command in Terminal – defaults write com.apple.finder FXEnableExtensionChangeWarning -bool true

And there you have it. You have now learnt how to successfully turn off the change file extension warning on Mac. It’s safe to disable this feature, but only if you know what you’re doing. As mentioned in the beginning, changing a file’s extension to an incompatible once could corrupt the file and make it unusable.

Wrapping Up

As you can see, disabling the change file extension warning on Mac is pretty simple and straightforward. It’s easy to turn it off, and just as easy to re-enable it. We hope this tutorial helped you out.