Category: Text tools
List Difference Tool
Compare two lists: only in A, only in B, and shared lines
Compare two newline-separated lists and see the lines only in the first, only in the second, in both, and their combined union, with options to trim whitespace and ignore case. Runs entirely in your browser.
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Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
Reconciling two lists, an old and a new export, two spreadsheets' worth of email addresses, a before and after set of file names, comes up constantly and is tedious to do by eye. This tool treats each list as a set of lines, deduplicates within each side, and buckets every line into only in A, only in B, the intersection, or the union, so the result is one of the four views a comparison usually needs.
How to use it
- Paste List A and List B, one item per line.
- Turn on Trim whitespace or Ignore case if the lists need it.
- Switch between Only in A, Only in B, In both and Union to see each result.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- Are my lists uploaded anywhere?
- No. Comparison happens in JavaScript running in the page, so nothing you paste ever leaves your device.
- Are duplicate lines within one list counted twice?
- No. Each list is deduplicated first, so a value repeated ten times in List A still counts once when compared against List B.
- What is the difference between Union and In both?
- In both (the intersection) is lines present in every list; Union is every distinct line from either list, combined.