How to compare two lists
Diffline finds the differences between two lists in a moment, whatever order the items are in:
- Add both lists. Paste the first list into the Original box and the second into the Changed box, one item per line. You can also click Open file to load a .txt or .csv file.
- Read the three lists. Only in Original shows items that are missing from the second list. Only in Changed shows items that are new. In both shows the items they share.
- Choose what counts as the same. Spaces around items and blank lines are always ignored. Tick Ignore case if Apple and apple are the same item to you.
- Copy what you need. Each list has its own Copy button, which copies every item, one per line, ready to paste into a spreadsheet or an email.
Tip: below the three lists you still get the full line by line comparison. It follows the order of the items, which helps when the order itself matters, such as a ranking or a playlist.
What you can compare
Email and mailing lists
Find who is on one list but not the other, for example subscribers who are missing from your new email tool, or attendees who registered but did not check in.
Spreadsheet columns
Copy a column from Excel or Google Sheets into each box to see which values match. It is often quicker than writing a VLOOKUP or MATCH formula.
Product codes and stock
Compare SKUs, order numbers or invoice IDs between two exports to find what was added, dropped or never shipped.
Names, files and keywords
Check a class or team list against last year's, the files in two folders, or two sets of keywords, and see what changed at a glance.
Lists where order matters
For rankings, steps or anything where the order is part of the meaning, use the line by line comparison below the lists, or compare two texts on the home page.
Why your lists stay private
Lists are often personal: email addresses, customer names, phone numbers or order IDs. Many online list tools send what you paste to their servers. Diffline does not. The comparison runs inside the page, on your own device, so your lists are never uploaded, stored or logged.
The same is true for the Copy buttons: they copy straight to your clipboard. You can read more in our Privacy Policy, or compare two text files instead.
Frequently asked questions
How do I compare two lists online?
Paste the first list into the Original box and the second list into the Changed box, with one item on each line. Diffline shows three lists straight away: the items only in the first list, the items only in the second, and the items in both. Each one has a Copy button.
Does the order of the items matter?
No. An item counts as in both lists wherever it appears, so you do not need to sort anything first. Below the three lists you also get the usual line by line comparison, which does follow the order, in case you need it.
What happens to repeated items?
Each item is listed once, in the place it first appears. Diffline tells you how many repeated items it found in each list, which is a quick way to spot duplicates in a mailing list or an export.
Can I compare two columns from Excel or Google Sheets?
Yes. Select the cells in one column, copy them and paste into the Original box, then do the same with the other column in the Changed box. Each cell lands on its own line. You can also open a .csv or .txt file that has one item per line.
Are capital letters and extra spaces ignored?
Spaces at the start and end of an item, and blank lines, are always ignored. Tick Ignore case so that Apple and apple count as the same item, and Ignore spacing so that extra spaces inside an item do not matter either.
Is it safe to compare email lists or customer data?
Yes. The comparison runs inside your browser, so your lists are never uploaded, stored or logged. Email addresses, customer IDs and order numbers stay on your device, and closing the tab removes them.