Compare Two Lists
Paste two lists and instantly see items in both, only in list A, only in list B, and the combined set — with case-insensitive and trim options.
What is the Compare Two Lists?
Compare Two Lists takes two pasted lists — one item per line — and runs the classic set operations on them: items present in both lists, items only in list A, items only in list B, and the merged union of everything.
- Four result buckets: intersection, only in A, only in B, union
- Per-bucket counts, copy buttons and downloads
- Case-insensitive and trim toggles
- Duplicates within each list are collapsed automatically
- Order-independent set comparison — not a line diff
- Runs entirely in your browser, works offline
How to use the Compare Two Lists
- 1
Paste your first list into box A, one item per line.
- 2
Paste your second list into box B.
- 3
Toggle case-insensitive matching and trimming to suit your data.
- 4
Read the counts, then copy or download the bucket you need: in both, only A, only B, or all combined.
About the Compare Two Lists
Compare Two Lists takes two pasted lists — one item per line — and runs the classic set operations on them: items present in both lists, items only in list A, items only in list B, and the merged union of everything. Each bucket comes with its own count and its own copy and download buttons.
It is the quick way to answer everyday data questions: which emails appear on both campaign lists, which SKUs are missing from the new export, which usernames were added or dropped between two snapshots. Case-insensitive matching and whitespace trimming make sure “Apple ” and “apple” count as the same item when you want them to.
Unlike a line-by-line diff, order does not matter here — the lists are compared as sets. And as always, the comparison runs 100% locally in your browser: neither list is ever uploaded.
Frequently asked questions
How is this different from a text diff tool?
A diff compares texts line by line in order, showing edits. This tool treats each list as an unordered set, so it tells you which items are shared or unique regardless of where they appear in each list.
Can I find items that are in one list but not the other?
Yes — that is the “Only in A” and “Only in B” buckets. Paste both lists and each bucket shows exactly what is missing from the other side, with a count.
Does capitalisation matter when comparing?
Only if you want it to. With case-insensitive matching on, “John@Example.com” and “john@example.com” are treated as the same item; switch it off for exact comparison.
What happens to duplicates inside one list?
They are collapsed before comparing, so each unique item is considered once. The counts reflect unique items, which is usually what list comparisons need.
Are my lists uploaded to a server?
No. Both lists are processed in your browser only — nothing is transmitted, so the tool is safe for customer emails and internal data.
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