How to: Compare two lists in different worksheets in Excel to locate any duplicates

Without VBA…

If you can use a helper column, you can use the MATCH function to test if a value in one column exists in another column (or in another column on another worksheet). It will return an Error if there is no match

To simply identify duplicates, use a helper column

Assume data in Sheet1, Column A, and another list in Sheet2, Column A. In your helper column, row 1, place the following formula:

=If(IsError(Match(A1, 'Sheet2'!A:A,False)),"","Duplicate")

Drag/copy this forumla down, and it should identify the duplicates.

To highlight cells, use conditional formatting:

With some tinkering, you can use this MATCH function in a Conditional Formatting rule which would highlight duplicate values. I would probably do this instead of using a helper column, although the helper column is a great way to “see” results before you make the conditional formatting rule.

Something like:

=NOT(ISERROR(MATCH(A1, 'Sheet2'!A:A,FALSE)))

remove_excel_duplicates

For Excel 2007 and prior, you cannot use conditional formatting rules that reference other worksheets. In this case, use the helper column and set your formatting rule in column A like:

=B1="Duplicate"

This screenshot is from the 2010 UI, but the same rule should work in 2007/2003 Excel.

 

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