Compare Lists Online

How to compare two lists

1. Paste the first list into List A.
2. Paste the second list into List B.
3. Adjust the comparison options if needed.
4. Review Differences, Only A, Only B, Matches or All, then copy or download the result you need.

List comparison results explained

The tabs show the same list comparison from different angles and keep the original list order. With Remove duplicates enabled, the outputs correspond to familiar set operations; with duplicates retained, repeated occurrences are matched as a multiset instead.

Differences

items that remain in only one list; with duplicates removed, this is the symmetric difference.

Only A

items or occurrences from List A with no pair in List B; with duplicates removed, this corresponds to A − B.

Only B

items or occurrences from List B with no pair in List A; with duplicates removed, this corresponds to B − A.

Matches

items found in both lists, shown in List A order; with duplicates removed, this is the intersection.

All

List A followed by values from List B not already represented; with duplicates removed, this is the union of the two lists.

Common ways to compare lists

People use this tool for everyday list tasks such as:

• email addresses
• customer or order IDs
• URLs
• product or SKU lists
• keywords and names
• columns copied from Excel or Google Sheets
• exports from two systems when you need to find missing records
• old and new inventory, URL or keyword exports during reconciliation

How your data is processed

The comparison runs entirely in your browser. Raw lists and result content are never uploaded to a server.

• Comparison options change matching rules while preserving the original line text shown in results.
• Copy uses the Clipboard API only after you click the button.
• Download creates a local text file on your device.
• The site does not save your lists in cookies, localStorage or sessionStorage.
• Raw input and results are not included in analytics or logging.

See the Privacy page for the full details.

Frequently asked questions

Can I compare two lists with duplicates?

Yes. Remove duplicates is enabled by default, so each list is compared as a set of unique values. Turn it off to compare repeated occurrences in each list.

Is the comparison case-sensitive?

Yes, by default. The Ignore case option changes the comparison key but not your raw text, so both spellings can match while the original input stays unchanged.

What does Ignore surrounding whitespace do?

It ignores spaces and tabs at the beginning and end of a line when deciding whether values match. The original line text is still preserved in the displayed results.

Can I compare columns from Excel or Google Sheets?

Yes. Copy a column and paste it into List A or List B. Each cell becomes one line, one item per line.

Are my lists uploaded to a server?

No. The comparison runs locally in your browser. Your list content is not uploaded to a server, not sent in network requests and not saved by the site. Copy and Download export the result only after you click the button.

What does “Only A” mean?

Only A shows the values or occurrences that exist in List A without a pair in List B, based on your current comparison options.