How to use it
- Paste list A on the left and list B on the right, one item per line.
- Set the options for case, spaces and empty lines.
- Read the four result boxes.
- Copy or download any of them.
The four results
| Result | Meaning | Set notation |
|---|---|---|
| In both | Items that appear in A and in B | A ∩ B (intersection) |
| Only in A | Items in A that are missing from B | A − B (difference) |
| Only in B | Items in B that are missing from A | B − A |
| Union | Every item from either list, once | A ∪ B |
Each box has its own Copy and Download button, and the four counts are shown on top. The labels above the input boxes show how many items each list has and how many of them are distinct.
Duplicates inside a list are counted once. Order doesn't matter: the comparison treats each list as a set. Results keep the order in which items first appear, or switch on Sort results A–Z.
Options
- Ignore case. On by default: Pear in one list matches pear in the other.
- Trim spaces. On by default: invisible spaces at the start or end of a line don't prevent a match.
- Skip empty lines. On by default.
- Sort results A–Z. Sorts all four outputs alphabetically.
- Swap A ⇄ B exchanges the two lists.
Example
List A: apple, pear, plum, peach, cherry List B: Pear, peach, orange, apple, kiwi
| Result | Items |
|---|---|
| In both | apple, pear, peach |
| Only in A | plum, cherry |
| Only in B | orange, kiwi |
| Union | apple, pear, plum, peach, cherry, orange, kiwi |
How matching works
Two items match when they are identical after the chosen normalization. That means small differences still count: Bob Smith and Robert Smith are different, anna@example.com and anna@example.com. (with a trailing period) are different, and Café and Cafe are different. If you expect such variations, clean both lists the same way first, for example by removing accents with remove accents or fixing punctuation with find and replace.
Everyday uses
- Email lists: find subscribers who are on the old list but missing from the new one, or remove unsubscribed addresses (Only in A, where B is the unsubscribe list).
- Attendance: compare the registration list with check-ins to see who didn't show up.
- Inventory: compare what the system says you have with what you counted.
- Keywords: see which keywords a competitor ranks for that you don't.
- Code and config: compare two lists of packages, environment variables or file names.
Copy a column from each spreadsheet into the two boxes. If the values are inside a larger table, pull out the right column first with extract columns. If the lists have stray invisible characters, remove extra spaces first.
For comparing two versions of a text where order matters, use text compare. To simply dedupe one list, use remove duplicate lines.
The comparison runs in your browser, so customer and employee lists stay private.
Excel alternative
In a spreadsheet you could use COUNTIF or XLOOKUP formulas to flag matches, but setting them up for both directions takes several columns. Pasting the two columns here gives you all four results at once, ready to copy back.
Frequently asked questions
How do I find common items in two lists?
Paste one list in each box. The “In both” box shows the items that appear in both lists.
How do I find items that are in one list but not the other?
Look at “Only in A” and “Only in B”.
Is the comparison case-sensitive?
Not by default. Turn off “Ignore case” to make Apple and apple different.
Does the order of the lists matter?
No. The lists are compared as sets, so order doesn't affect the result.
Can I compare columns from Excel?
Yes. Copy each column and paste it into one of the boxes.
Last updated: November 12, 2026