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

The easiest way to do it, at least for me, is:

Conditional format-> Add new rule->Set your own formula:

=ISNA(MATCH(A2;$B:$B;0))

Where A2 is the first element in column A to be compared and B is the column where A's element will be searched.

Once you have set the formula and picked the format, apply this rule to all elements in the column.

Hope this helps