Compare Two Lists

By line. Put one item per line in each box. Blank lines are ignored, and surrounding whitespace is trimmed by default so a stray space does not make two otherwise identical items look different.

Yes. Tick 'Ignore case' so 'Apple' and 'apple' count as the same item. The result keeps the original casing from the first time an item appears, so the output stays readable.

Duplicates within a single list are collapsed to one entry before comparing, and the first occurrence wins. That means each item is counted once and the counts shown next to each group reflect distinct items.

The union is every distinct item across both lists combined. It lists List A's items first, in their original order, followed by any items that appear only in List B.

Yes. Items keep the order they first appear in. 'Only in A' and 'In both' follow List A's order, 'Only in B' follows List B's order, and the union chains A then B's new items.

They are the same thing. 'In both' is the set intersection, the items that appear in List A and also in List B, and 'Only in A' plus 'Only in B' is the symmetric difference.

Yes. The compare runs in your browser using hash sets, so even large lists resolve quickly. The practical ceiling is your device memory rather than a fixed row limit.

Yes. This tool exposes a JSON endpoint that accepts listA and listB strings plus optional caseInsensitive and trim flags, and returns onlyA, onlyB, both, and union arrays.

Yes when you use the tool in the browser. The comparison happens locally and nothing is uploaded, so pasted lists never leave your device.