List Compare

What it's for

Compare two lists and see what’s in one but not the other, what they share, and everything in either, with duplicates removed. It’s the quick answer to “who’s missing?” without a spreadsheet formula.

For example, when you have the list of people invited and the list of people who replied, paste both to see who hasn’t answered yet.

How to use it

Paste one list into List A and the other into List B, one item per line, or choose commas, tabs or spaces as the separator. The four results update as you type, each with its count and a Copy button: Only in A, Only in B, In both and In either, once each. Tick Ignore capitals to treat Bob and bob as the same item. Spaces around items and blank lines don’t count. Copy a link to this input keeps both lists.

Example

Choose Try an example, which fills in two short lists of email addresses. Only in A shows alice@example.com, bob@example.com and dave@example.com; only in B shows Bob@example.com and erin@example.com. Tick Ignore capitals and Bob moves to In both, beside Carol.

Good to know

Items are compared exactly, apart from capitals when you ask, so Smith, J and J Smith are different items. Each result keeps an item’s first spelling. For a line-by-line comparison of two versions of a text, in order, use the Diff Checker instead.