List Intersection (Common Items)
Find items that appear in both lists. Case-sensitive toggle included. Free online intersection calculator. All processing in your browser.
Why Use the List Intersection Tool?
Finding common items between two datasets is a fundamental operation in data analysis, database management, and quality control. Our List Intersection Tool instantly identifies shared elements between two lists with optional case-insensitive matching.
Key Features
- Instant intersection of two lists with deduplicated results
- Case-sensitive toggle for flexible matching
- Real-time statistics showing item counts for both lists
- One-click copy of intersection results
How to Use
- Enter your first list in the List A textarea
- Enter your second list in the List B textarea
- Toggle case-sensitivity and view common items instantly
Technical Details
This tool uses JavaScript Set data structures for efficient O(n+m) intersection computation. When case-insensitive mode is enabled, items are compared by their lowercase equivalents while preserving the original case in the output. All processing happens client-side.
FAQ
What happens with duplicate items?
Duplicates are deduplicated in the result. Each common item appears only once, regardless of how many times it appears in either list.
How does case-insensitive matching work?
When case-insensitive mode is on, 'Apple' and 'apple' are considered the same item. The output preserves the casing from List A.
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