List Comparison

Compare two lists to find items unique to each list and items in common.

Compare lists

Enter items in each list (one per line) to compare them. Find unique items and common items between lists.

List A

0 items

List B

0 items

Only in A

0

No unique items

In Both

0

No common items

Only in B

0

No unique items

About

About the List Comparison

The List Comparison tool takes two lists — one item per line — and instantly shows which items are only in the first, only in the second, and in both. Paste in emails, SKUs, IDs, URLs, or usernames and get three result sets you can copy individually or all at once, with case sensitivity and whitespace handling under your control. Everything runs in your browser, so lists containing customer data or internal identifiers never leave your machine.

How to use the List Comparison

  1. 1Paste your first list into List A, one item per line.
  2. 2Paste your second list into List B.
  3. 3Adjust the options if you need to: case sensitivity (off by default), trim whitespace (on), ignore empty lines (on).
  4. 4Read the three panels — Only in A, In Both, Only in B — which update as you type.
  5. 5Copy any single panel, or use Copy All Results to get all three with headings.

Common use cases

  • Finding which email addresses are on one mailing list but not another
  • Diffing two exports to see exactly what was added or removed
  • Comparing SKUs, order IDs, or user IDs across two systems
  • Checking which sitemap URLs are missing from a crawl
  • Seeing the overlap between two sets of records before merging them

Frequently asked questions

How does it handle duplicates within a list?

Results are deduplicated, so an item appearing three times in List A shows once. That's ideal for comparing two sets, but it does mean the tool can't be used to count duplicates inside a single list.

Is the comparison case sensitive?

Not by default — Apple and apple are treated as the same item. Turn on Case sensitive for exact matching, which matters when you're comparing IDs, hashes, or anything where case is meaningful.

What if my lists have stray spaces?

Trim whitespace is on by default, so leading and trailing spaces are ignored and ' apple' matches 'apple'. Turn it off only if the spacing itself is significant.

What counts as one item?

One line is one item. The tool splits on line breaks, so entries containing spaces or commas are fine — but a comma-separated list on a single line is read as one long item. Put each entry on its own line.

Is my data private?

Yes. The comparison runs entirely in your browser. Nothing you paste is uploaded, stored, or logged, so it's safe for customer emails or internal identifiers.

Your data never leaves your browser • No cookies • Works offline after your first visit

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