How to Compare Two Lists

Which customers are on this month’s list but not last month’s? Which files are missing from a backup? Comparing two lists answers questions like these in seconds.

Open Compare Two Lists

Step by step

  1. Open Compare Two Lists

    Or open a focused tool: Find Common Items, Only in List A, Only in List B or Find Differences.

  2. Fill in both lists

    Paste the first list into List A and the second into List B, one item per line. You can also upload a file for each list.

  3. Pick what you want to see

    Common shows items in both lists. Only in A and Only in B show what each list has that the other doesn’t. Differences shows both of those together, and All unique shows everything once.

  4. Compare and export

    Press Compare lists, then copy the result or download it as TXT, CSV or JSON.

Example

Before
List A: apple, banana, cherry
List B: banana, cherry, date
After
Common: banana, cherry
Only in A: apple
Only in B: date

Each item goes on its own line in the tool.

Avoid false differences

Leave “Trim whitespace” on so that “apple ” and “apple” match, and leave “Case-sensitive” off unless capitalization really matters. If your lists come from different systems, run them through List Cleaner first.

In Excel

Next to List A, use COUNTIF to check whether each item appears in List B. A result of 0 means the item is only in List A.

=COUNTIF($B:$B, A2)

In Google Sheets

FILTER and COUNTIF together return the items of List A that are missing from List B.

=FILTER(A2:A, COUNTIF(B2:B, A2:A)=0)

On the command line

comm compares two sorted files: -23 prints lines only in the first file, -13 lines only in the second, and -12 lines in both.

comm -23 <(sort a.txt) <(sort b.txt)

Try Compare Two Lists

Compare two lists and find what’s shared and what’s different.

Open Compare Two Lists

Frequently asked questions

Does the order of the lines matter?

No. Lists are compared as sets; results follow the order in which items first appear.

Can I combine the two lists instead?

Yes — use Merge Lists, which can remove duplicates across both lists.