ComparLab
Lists

Local list processing

Compare Two Lists Online

Find items that appear only in List A, only in List B, or in both. Control duplicates, whitespace, letter case, and sorting.

List A

One item per line

List B

One item per line

List results will appear here

Enter one item per line in each panel.

How to compare lists

Add one value per line, choose how values should be normalized, and run the comparison. Copy any result group directly for use in a spreadsheet, email, script, or cleanup workflow.

Where list comparison helps

  • Compare subscriber, inventory, or identifier exports.
  • Find missing values between two system reports.
  • Deduplicate keyword and tag collections.

Related comparison tools

Compare free-form text, compare JSON objects, or review source code changes.

Frequently asked questions

How does List Diff treat duplicates?

Ignore duplicates is enabled by default. Turn it off to preserve repeated entries in the result.

Does list order matter?

Membership comparison does not depend on order. Results preserve List A or List B order unless you enable sorting.

Are my lists uploaded?

No. The lists are compared locally and remain in this browser tab.