We show you how to highlight duplicates in Google Sheets using the COUNTIF and ARRAYFORMULA functions under the conditional format rules.

Install the Remove Duplicates add-on from the Google Workspace Marketplace. In your sheet, click Extensions, then Remove Duplicates, and choose: Find Duplicates or Uniques.

The duplicates will be highlighted in the A column. Google Sheets also provides further customization options for highlighting duplicates such as making them bold or changing their color.

Once we started using Google Sheets’ built-in tools to highlight duplicates, it became one of those productivity hacks we rely on every single month.

Learn how to sort columns alphabetically and numerically to make finding info easier. Here's how to sort in Google Sheets.