Excel compare two columns and highlight duplicates

Question

I have an excel file with 10,000 rows in column A some values are the same.

Example:

A1 - P7767

A2 - P3443

A3 - P7767

A4 - P8746

A5 - P9435
         


        

Answer 1

Suppose you want to compare a column A and column H in a same spreadsheet .

You need to go another column next to these 2 columns and paste this formula : =(Sheet1!A:A=Sheet1!H:H) this will display FALSE or TRUE in the column . So you can use this new column to color the non matching values using conditional color formatting feature .