Google-sheets – Conditional formatting of duplicate values

conditional formattinggoogle sheets

In a full sheet range, I need a cell to be highlighted when a duplicate is typed, whether it is a number (phone number in this case) or a text string (name in my case). Both the new cell and the cell it is duplicating need to be highlighted.

I've tried the "countif" formula but to no avail. If it matters, I'm in a French version of Sheets.

Best Answer

This formula should do the trick. Assumes your range begins at a1 and ends at a100. Adjust as needed.