How to compare two lists online
- Paste your first list into List A and the second into List B — one item per line, or choose a different delimiter. You can also drop text or CSV files onto either box.
- Pick your matching rules: ignore case, spaces, leading zeros or punctuation, or compare only one column of a CSV.
- Read the results: items only in A, items in both, items only in B, and the combined list.
- Copy or download any result, or use Send to to move it into A or B for a follow-up comparison.
What the results mean
A only
Items that appear in List A but not in List B (the set difference A − B).
In both (A ∩ B)
The intersection — items found in both lists.
B only
Items that appear in List B but not in List A (B − A).
All (A ∪ B)
The union — every unique item from either list.
In one list only
The symmetric difference — items in A or B but not both. Ideal for spotting everything that changed.
Duplicates
Items that appear more than once within the same list.
Common uses
- Find new or missing records between two database or CRM exports
- Compare two Excel or Google Sheets columns for differences
- Check which email subscribers appear on one list but not another
- Diff keyword lists, URL lists, SKUs, usernames or inventory
- De-duplicate a list by pasting it in List A and reading “All (A ∪ B)”
Frequently asked questions
How do I find items that are in one list but not another?
Paste the lists into List A and List B. “A only” shows what is in A and missing from B; “B only” shows the reverse.
Can I upload a file instead of pasting text?
Yes. Drag a .txt, .csv or .tsv file onto either list box or use “Open file…”. The file is read locally and is never uploaded.
Can I compare lists case-insensitively?
Yes. Leave “Case sensitive” unticked (the default) so Apple and apple match. Results keep the original spelling from your list.
How do I compare two Excel columns for differences?
Select the first column in Excel, copy it and paste into List A, then do the same for List B in the second box. Excel copies a column as one item per line, which is the default format.
Can I compare only one column of a CSV?
Yes. Enter a column number under “Compare on column”. Each row is matched on that column (commas, semicolons and tabs are detected) while the full row is kept in the output.
How do I handle extra spaces or leading zeros?
Tick “Ignore leading/trailing spaces”, “Ignore extra spaces” and “Ignore leading zeros” so 007, 7 and 7 are treated as the same value.
What is the “Similarity” score?
It is the Jaccard similarity: the number of items in both lists divided by the number of unique items across both. 100% means the lists contain exactly the same items.
Are my lists stored anywhere?
No. Everything runs in your browser. Nothing is uploaded, and there is no account. Your option choices are remembered on your device only.