How to use the Compare Two Lists
- Paste the first list into List A and the second into List B — one item per line, or separated by commas.
- Choose whether upper/lower case and extra spaces should matter.
- Read the four results: only in A, only in B, in both, and combined.
- Copy or save any of the result lists.
What does this tool do?
Comparing lists is a set problem, not a text-diff problem: you want to know which values appear where, regardless of order. The tool treats each list as a set of values — the same as Excel's MATCH or COUNTIF tricks, without the formulas — and splits them into the difference (A − B and B − A), the intersection (A ∩ B) and the union (A ∪ B).
Matching ignores upper/lower case and extra spaces by default, so “Apple” and “ apple ” count as the same item. Each result keeps the item in the form it first appeared, lists every value only once, and can be sorted alphabetically or naturally (so item2 comes before item10).
Why use it?
- Four answers at once: only A, only B, both and combined.
- Works with lines or comma-separated items.
- Counts repeated items inside each list.
- Copy or save each result separately.
Use cases
- Find which email addresses from one export are missing in another.
- Check which SKUs, invoices or student IDs appear in both systems.
- Merge two keyword or guest lists without duplicates.
Example
List A: apple, banana, cherry, date, elderberry. List B: banana, Date, fig, grape, apple.
| Result | Items |
|---|---|
| Only in A | cherry, elderberry |
| Only in B | fig, grape |
| In both | apple, banana, date |
| Combined | apple, banana, cherry, date, elderberry, fig, grape |
Accuracy and limits
- Items are matched exactly after the case and spacing rules you choose; “colour” and “color” are different items.
- Everything runs in your browser; your lists are never uploaded.
Privacy
Everything you type is processed in your browser. Nothing you enter is sent to our servers or stored by us. There's no account to create and nothing to install.
Frequently asked questions
Does the order of the lists matter?
No. Lists are compared as sets. To see line-by-line changes between two versions of a document, use the Diff Checker.
What about duplicates inside one list?
They're counted and reported, and each value appears once in the results. To clean duplicates from a single list, use Remove Duplicate Lines.
My items are in a spreadsheet column. Will that work?
Yes — copy the column and paste it; each cell becomes a line. For whole rows with several columns, CSV Compare is the better tool.
Last reviewed by the M2Toolkit team.