List Compare

Set operations on two lists: intersection, union, difference.

List Compare runs set operations on two lists of lines: intersection, union, difference, and symmetric difference. Paste one item per line into list A and list B, pick an operation, and get the matching lines back. It is handy whenever you need to diff or merge two text lists without writing a script.

Common uses

• Find items that appear in both lists (intersection), for example shared user IDs, emails, or SKUs
• Merge two lists into one deduplicated set with the union operation
• Find entries that exist only in list A or only in list B to spot what was added or removed
• Get the symmetric difference to see items present in exactly one list but not both
• Deduplicate and compare exported data such as allowlists, feature flags, or config keys

FAQ

Is my data sent to a server?

No. List Compare runs entirely in your browser and nothing is uploaded. Both lists stay on your device.

How should I format the two lists?

Enter one item per line in each list. Each line is trimmed of surrounding whitespace, and empty lines are ignored.

Does it remove duplicate entries?

Yes. The result is deduplicated, so each matching item appears only once regardless of how many times it occurs in the input.

Is the comparison case-sensitive?

Yes. Items are compared as exact strings after trimming, so "Apple" and "apple" are treated as different entries.

What operations are supported?

Five set operations: in both (intersection), in either (union), only in A, only in B, and in one but not both (symmetric difference).

Related tools

• CSV Diff
• HTML Diff
• JSON Diff
• Text Diff
• XML Diff
• YAML Diff