Highlight Duplicate Column Cells In Google Sheets
Assume you have data like below and want to highlight the duplicate values:
| Names |
| Liam |
| Noah |
| Oliver |
| Elijah |
| Henry |
| Alexander |
| Oliver |
| William |
| James |
| Benjamin |
| Lucas |
| Noah |
To highlight, click on "Format" and select "Conditional Formatting"
Now select formatting RULE as "Custom Formula" and enter below formula.
=countif(A:A,A1)>1