I recorded this video to show how to highlight duplicate values in Google Sheets — something I use constantly when working with data, lists, or customer info. Here’s the tutorial:

Whether you’re dealing with email lists, product IDs, or names, spotting duplicates quickly can save you a ton of time. In the video, I show how to use Conditional Formatting to automate it.

Here’s the basic process:

  1. Select the column or range
  2. Go to Format > Conditional Formatting
  3. In the formula box, enter:
    =countif(A:A, A1) > 1
  4. Choose a highlight color and click Done

This instantly flags all duplicate entries in the selected range.

You can apply this to single columns, entire rows, or multiple sheets. It’s perfect for cleaning up spreadsheets before importing them into CRMs, email tools, or analytics platforms.

I use this every time I build lead lists, manage CSV exports, or prep data for a project.

Have you tried this technique before? What kind of data do you usually clean up?