Compare Two Lists
| Match rule | What counts as equal | Use it for |
|---|---|---|
| Exact + trim (default) | same line, outer spaces ignored | email lists, SKU lists |
| Ignore case | Apple = apple | names, tags, domains |
| Exact, case-sensitive | every byte must match | codes, config keys, IDs |
Paste two lists into the boxes and this page splits them three ways on the spot: items in both lists, items only in list A, items only in list B. Two 1,000-line lists compare in well under 50 milliseconds because the whole job is a single pass over each list building a set - no uploads, no waiting, and a Download button hands you the full three-section report as a text file.
The classic jobs: checking which email subscribers dropped off between two exports, which SKUs a supplier quoted that your catalog lacks, which files made it into the backup and which did not. Blank lines are skipped automatically, and if a line appears twice inside one list that duplicate is counted and reported rather than silently swallowed - the number one way list comparisons quietly lie.
How to use
- Paste your first list into box A and the second into box B - one item per line, any order.
- Read the three groups: shared items first, then items unique to each side. Turn on Ignore case if Apple and apple should count as the same item.
- Hit Download comparison (.txt) to keep the full report, or copy the section you need straight out of the box.
Frequently asked questions
Does the order of items matter?
No. This is a set comparison: what matters is whether an item exists on each side, not where it sits. If you need an order-sensitive, line-by-line diff (which paragraph moved where), use the text compare tool instead - it shows additions and removals in reading order.
What happens if a list has duplicate lines?
Duplicates never distort the result. Each list collapses to its distinct items before comparing, but the duplicate count is reported at the bottom of the result - so if list A contains support@ twice you will see '1 duplicate in A' instead of a mysterious mismatch.
How large can the lists be?
Comfortably tens of thousands of lines each - the comparison itself is linear in list size. The display caps what it prints so the page stays responsive, but the downloaded report always contains every line.
Is my data uploaded anywhere?
No. Both lists are compared inside this browser tab with plain JavaScript - nothing leaves your device, which is exactly why the comparison is instant no matter how sensitive the lists are.