# Changing file extension warning

Choose whether to display a warning when changing a file extension.

  • Tested on macOS:
    • Big Sur
    • Catalina
    • Mojave
  • Parameter type: bool

# Set to true (default value)

Display a warning when changing a file extension in the Finder

defaults write com.apple.finder "FXEnableExtensionChangeWarning" -bool "true" && killall Finder

# Set to false

Do not display the warning

defaults write com.apple.finder "FXEnableExtensionChangeWarning" -bool "false" && killall Finder

# Read current value

defaults read com.apple.finder "FXEnableExtensionChangeWarning"

# Reset to default value

defaults delete com.apple.finder "FXEnableExtensionChangeWarning" && killall Finder