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?
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? 


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:



Here's a quickanddirty 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 


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



Took me forever to figure this out but it's very simple. Assuming data begins in A2 and B2 (for headers) enter this formula in C2:
Then click and drag down. A cell with Please note that you need to change $A$287 to match your entire search array in Column A. For instance if your data in column A goes down for 1000 entries it should be $A$1000. 


My requirements was not to highlight but to show all values except that are duplicates amongst 2 columns. I took help of @brenton's solution and further improved to show the values so that I can use the data directly:
Copy this in the first cell of the 3rd column and apply the formula through out the column so that it will list all items from column B there are not listed in column A. 

