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List Compare

Free online list comparison tool. Paste two lists and instantly see items only in List A, items only in List B, and items in both. Includes a Jaccard similarity score. No signup required.

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0List A
0Only A
0In both
0Only B
0List B
List A
List B
Only in A0

Paste a list above

In both0

Paste a list above

Only in B0

Paste a list above

Options

How to compare two lists

  1. Paste List A into the first input box — one item per line.
  2. Paste List B into the second input box — one item per line.
  3. Read the results — three colour-coded columns appear instantly: items only in A (orange), items in both (green), and items only in B (blue).
  4. Check the similarity score in the toolbar — a Jaccard percentage showing how much the two lists overlap.
  5. Copy any column using the copy icon in its header to grab just the section you need.

What the similarity score means

The similarity percentage is the Jaccard similarity coefficient — the number of items in common divided by the total number of unique items across both lists. It is one of the most widely used metrics for comparing sets in data science and information retrieval.

100% Identical lists — every item appears in both.
75–99% High overlap — minor additions or deletions between versions.
40–74% Moderate overlap — significant differences worth reviewing.
15–39% Low overlap — mostly different lists with some shared items.
0–14% Very different — almost no items in common.

Common use cases

SEO keyword gap analysis

Compare your keyword list with a competitor's to find keywords they rank for that you don't, and vice versa.

Mailing list changes

Compare this month's subscriber export with last month's to find new subscribers (only in B) and churned subscribers (only in A).

Permission audit

Compare two access control lists to find who has access in one system but not another.

Product feature comparison

Compare feature lists across two products or two versions to identify what each has that the other lacks.

Data migration check

After migrating records, compare source IDs with destination IDs to find any that were missed (only in A) or added (only in B).

Tag or label consistency

Compare tags applied in two systems to find inconsistencies or missing taxonomy terms.

Frequently Asked Questions

How do I compare two lists?

Paste List A into the first box and List B into the second box — one item per line. The tool instantly shows you items only in A, items only in B, and items in both. Each result column has its own copy button.

What does the similarity percentage mean?

The similarity score is the Jaccard similarity coefficient — the number of common items divided by the total number of unique items across both lists. A score of 100% means the lists are identical. 0% means they share no items. 50% means half of all unique items appear in both lists.

Is the comparison case-sensitive?

No — by default "Apple" and "apple" are treated as the same item. Enable the Case-sensitive toggle if you need exact character matching.

What if an item appears multiple times in one list?

The comparison treats each list as a set — duplicates within the same list are ignored. An item is either in a list or it is not. To remove intra-list duplicates before comparing, use the Duplicate Line Remover first.

What are practical uses for list comparison?

Common uses include: comparing keyword exports from two SEO tools, finding new subscribers since last month, identifying users on two permission lists, checking which features are in two product specs, or auditing tag overlap between content sets.

Can I copy individual result sections?

Yes. Each of the three result columns — Only in A, In Both, Only in B — has its own copy button. Copy just the section you need.

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