That way, they pop out from the rest of the data set.
Here’s how it works usingconditional formatting:
Highlight the cells you want to search through.
Go toFormat>Conditional formatting.

Confirm the cell range is what you selected earlier.
In theFormat cells ifdrop-down menu, selectCustom formula is.
A new field appears below it.

We’ve chosen red in this example.
Alternatively, you might define the text color by selecting theAin the formatting bar.
SelectDoneto apply the conditional formatting.

All duplicates should now have a red-filled cell.
bang out=UNIQUE(into the cell, and then pick the column letter above your list of data.
The formula will automatically add the whole range for you.

PressEnterto close up the formula.
The unique data is displayed in that column, starting in the cell where you entered the formula.
Among the many that are available are some that are built specifically for finding duplicate information.

Install Ablebits' Remove Duplicates add-on for Google Sheets and use the Compare Columns or Sheets tool.
Go toExtensions>Remove Duplicates>Compare columns or sheets.