Find Common Items in Two Lists
Paste two lists and instantly see which items appear in both. Find overlap, shared records, and cross-list duplicates in seconds.
Paste your lists to get started
Add items to List A and List B, then pick an operation to see results instantly. Use the delimiter selector to match your input format.
When to Use List Intersection
Intersection answers the question: "What do these two lists have in common?" Common scenarios include:
- Shared customers — Find which contacts exist in both your CRM and email platform.
- Overlapping keywords — Discover which keywords you and a competitor both target.
- Confirmed records — Match expected IDs against actual records to confirm successful processing.
- Mutual connections — Find people who appear in two different social or professional lists.
Need to find what's missing instead? Try the difference tool. Want to merge both lists into one? Use the merge tool. Comparing email lists? Check out our email list comparison page.
Frequently Asked Questions
- What is list intersection?
- List intersection finds items that appear in both lists simultaneously. If List A has [apple, banana, cherry] and List B has [banana, cherry, date], the intersection is [banana, cherry] — the items they share in common.
- How do I find duplicates across two lists?
- Paste both lists into the panels and click A ∩ B (intersection). The results show every item that appears in both lists. These are your cross-list duplicates — items shared between both datasets.
- Is this the same as finding duplicates within a single list?
- No. Intersection finds items common to two separate lists. To find duplicates within a single list, paste the same list into both panels — items that appear more than once will show up when you toggle the "Deduplicate" option off and use A − B.
- Can I find mutual followers or shared contacts?
- Yes. Paste your following list into List A and your followers list into List B. The intersection (A ∩ B) gives you mutual connections — people who appear in both lists.