Compare lists
Compare two lists to find what is only in the first, only in the second, in both, or in either.
List A
List B
Only in A
What it does
Paste two lists, one item per line, and see how they differ. The four answers are always counted and one is shown at a time: the items only in list A, the items only in list B, the items in both, and the items in either.
Results keep the order in which items first appear, with list A first, so the output lines up with what you pasted.
How to use it
- Paste the first list into List A and the second into List B.
- Pick the result you want. Each choice shows how many items it has, so you can see all four counts at a glance.
- Turn on Ignore case if capital letters should not matter. Trim spaces is on to begin with, because stray spaces are the usual reason two matching items do not match.
- Press Copy, or Download to save the result as a text file.
It is a quick way to check a list of email addresses against the ones already sent to, find the IDs present in one export and absent from another, or merge two lists without repeats.
Questions
What do the four results mean?
"Only in A" is what the first list has and the second does not. "Only in B" is the reverse. "In both" is what the two lists share. "In either" is everything from both lists with repeats removed.
How do I find what is missing from a list?
Put the complete list in A and the list you are checking in B, then choose "Only in A". Those are the items the second list is missing.
What happens to an item that appears twice in the same list?
It counts once. Each list is treated as a set of different items, so repeats and blank lines do not change the result. The count above each list is the number of different items in it.
Why are two items that look the same treated as different?
Usually a difference in capital letters or a space you cannot see. Turn on "Ignore case" so that "Apple" matches "apple", and keep "Trim spaces" on so that spaces at the start or end of a line are ignored.
Are my lists sent anywhere?
No. The comparison runs in your browser. Nothing is uploaded or stored, and both lists are gone when you close the tab.