Excel: Find Items in one column that are not in another column

Question

I have two columns in excel, and I want to find (preferably highlight) the items that are in column B, but not in column A.

What's the quickest way to do this?

Answer 1

1. Select the list in column A
2. Right-Click and select Name a Range...
3. Enter "ColumnToSearch"
4. Click cell C1
5. Enter this formula: =MATCH(B1,ColumnToSearch,0)
6. Drag the formula down for all items in B

If the formula fails to find a match, it will be marked #N/A, otherwise it will be a number.

If you'd like it to be TRUE for match and FALSE for no match, use this formula instead:

=IF(ISNA(MATCH(B1,ColumnToSearch,0)),FALSE,TRUE)

Answer 2

Here's a quick-and-dirty method.

Highlight Column B and open Conditional Formatting.

Pick Use a formula to determine which cells to highlight.

Enter the following formula then set your preferred format.

=countif(A:A,B1)=0

Answer 3

See my array formula answer to listing A not found in B here:

=IFERROR(INDEX($A$2:$A$1999,MATCH(0,IFERROR(MATCH($A$2:$A$1999,$B$2:$B$399,0),COUNTIF($C$1:$C1,$A$2:$A$1999)),0)),"")

Comparing two columns of names and returning missing names