Set Operations Calculator
Free online set operations calculator. Compute the union, intersection, difference, and symmetric difference of two lists with instant cardinality, subset, and equality checks. 100% client-side.
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What is Set Operations Calculator?
The Set Operations Calculator is a free, browser-based tool that computes the four fundamental set-theory operations on any two lists of items. Enter Set A and Set B — numbers, IDs, tags, or strings — and instantly see the union, intersection, difference, and symmetric difference, each with its cardinality. The tool also detects whether one set is a subset of the other and whether the two sets are equal. Everything runs locally in your browser, making it ideal for data cleaning, list comparison, and quick set-theory work without writing any code.
Key Benefits
- Four operations in one view: union, intersection, difference, and symmetric difference
- Automatic deduplication so every set holds only unique items
- Live subset and equality badges that show the relationship between A and B
- Flexible separators: commas, spaces, semicolons, or new lines all work
- 100% client-side — your data never leaves your browser
Common Use Cases
- •Find common elements between two lists of IDs or usernames
- •Combine two lists while removing duplicates into one unique set
- •Check which items were added or removed between two data exports
- •Verify subset or equality relationships in set-theory homework
- •Compare tags, categories, or keywords between two collections
How to Use the Set Operations Calculator
- Enter Set A: Type or paste the items of your first list into the Set A box. Separate items with commas, spaces, semicolons, or new lines — for example: 1, 2, 3, apple, banana. Duplicates are removed automatically.
- Enter Set B: Fill in the items of your second list in the Set B box using the same separators. You can leave Set B empty if you only want to inspect Set A, though operations need both sets.
- Read the Results: All four operations — Union, Intersection, Difference (A − B), and Symmetric Difference — appear instantly below with their size. The subset and equality badges show the relationship between A and B.
- Copy What You Need: Click Copy next to any result to copy that set, or click Copy all results to copy all four as formatted text. Use Swap to swap A and B, or Clear to start over.
Key Features
- Compute all four core operations at once: union (∪), intersection (∩), difference (−), and symmetric difference (△)
- Automatic deduplication so each set contains only unique items, with live cardinality shown for every result
- Instant subset and equality badges showing whether A ⊆ B, B ⊆ A, or A = B
- Flexible parsing that accepts commas, spaces, new lines, or semicolons and mixes numbers with text
- One-click copy for any individual result, or copy all four results as formatted text
- 100% client-side — your lists never leave your browser, no signup required