Compare Two Lists
Find what's only in one list, only in the other, or in both.
By Syed Mubashir Ali · Last updated
Find what's missing from either list
Try an example compares two mailing lists. List A has anna, ben, carla, dev and Ella (with ben twice); list B has ben, carla, ella, farah and gus. With Ignore case ticked, Ella and ella match, and the result is:
Only in A (2): anna@example.com, dev@example.com Only in B (2): farah@example.com, gus@example.com In both (3): ben@example.com, carla@example.com, Ella@example.com
- Remove Duplicate Lines: Remove repeated lines from a single list first.
- Sort Lines: Sort a list alphabetically, by length or at random.
- Diff Checker: Compare two texts line by line and word by word instead.
Sets or counts: how repeats are handled
By default each list is treated as a set: an item that appears three times counts once, and the result says how many repeats each list had. That's right for questions like "who is on both lists?".
Tick Count repeats when the number of times matters, as with stock counts or order lines. Then an item listed twice in A and once in B shows once in In both and once in Only in A.
How to Use Compare Two Lists
- 1Paste the first list into List A and the second into List B, one item per line. Switch Split items to Commas for comma-separated lists.
- 2Three columns appear straight away: items only in A, items only in B, and items in both, each with a count.
- 3Leave Trim spaces on so stray spaces don't stop items matching, and tick Ignore case to match Apple with apple.
- 4Tick Count repeats when quantities matter, so an item twice in A and once in B leaves one copy only in A.
- 5Choose A–Z to sort the results, with numbers in number order, or keep each list's own order.
- 6Copy a column, or download all three as a CSV with each item and where it was found.
Frequently Asked Questions
How do I compare two lists?
Paste one list in each box, one item per line, or switch to Commas for comma-separated items. Three columns show what's only in list A, only in list B and in both; copy any column, or download all three together as a CSV.
Can I compare two columns from Excel or Google Sheets?
Yes. Select a column, copy it and paste it into one box: each cell arrives on its own line. Do the same with the other column. This compares single columns of values; it doesn't match whole rows across several columns.
Do capital letters and extra spaces matter?
Spaces at either end don't, because Trim spaces is on. Capital letters do count until you tick Ignore case, which then matches Apple and apple and shows each item as it was first written.
What happens to repeated items?
By default each list is treated as a set: a repeated item is listed once, with a note saying how many repeats each list has. Tick Count repeats to compare quantities, so an item twice in A and once in B leaves one copy in Only in A.
How many items can it compare?
It was tested with 100,000 items in each list, which compares in well under a second. Each column shows the first 5,000 items, and Copy and the CSV download include every item.
Is my list uploaded anywhere?
No. The lists are compared in your browser, so email addresses, customer numbers and other private lists never leave your device.
About Compare Two Lists
Two lists, and the question is always the same: what's in one but not the other? Last month's subscribers against this month's, the SKUs in the warehouse export against the ones on the website, the attendees who registered against those who turned up. Compare Two Lists answers it in one step, with three columns: only in the first list, only in the second, and in both.
It's built for lists pasted from wherever they live. A column copied from Excel or Google Sheets arrives one item per line; a comma-separated list from an email works with Split items set to Commas. Spaces at either end are ignored, capital letters can be, and repeats are either collapsed or counted, so the result answers the question you're actually asking.
Everything happens in your browser, which matters when the lists are email addresses, customer numbers or order IDs: nothing is uploaded, and closing the tab clears it.