Compare Two Lists Online

Q: Who doesn't follow me back on Instagram?

Use the Instagram template to load some sample data. Then paste the accounts you follow into List A and your actual followers into List B. Whatever shows up in Only in A is who isn't following you back.

Paste two lists to find differences, duplicates, and common items in your browser.

List A

0 items

List B

0 items

Delimiter Case Sensitive Trim Ignore Empty Dedupe Sort

Find & Replace: Regex

Only in List A 0

Only in List B 0

In Both Lists (Shared) 0

Format: Count (x3)

Matches: 0 Unique A: 0 Unique B: 0 Total: 0 Similarity: 0%

Visual Diff Inspector

List A View

Run comparison to view diff.

List B View

Run comparison to view diff.

Compare two lists

Paste two lists into the boxes above and click Compare. You'll instantly see three things: items only in the first list, items only in the second, and items that appear in both. No VLOOKUP, no spreadsheet detour.

Fast, private, in-browser list comparison. No signup required, works offline, and your data never leaves your device.

How to Compare Lists and Find Differences

All three result boxes appear at the same time - you don't have to switch between tabs or views
By default it splits on line breaks, but you can switch to comma, tab, semicolon, pipe, or write a regex
There's a trim option that strips leading/trailing whitespace, which saves a lot of headaches with copy-pasted data
You can add a prefix or suffix to the output, or force everything to lowercase - handy for cleaning up SQL lists
The side-by-side diff view highlights exactly which lines changed, useful when you're debugging config files or ID lists

Compare Lists Without Leaving Your Tab

Install the CompareLists Chrome Extension to compare lists from any tab, no need to open this site. It runs the same fast, private, in-browser comparison, right where you're already working.

Add to Chrome - It's Free!

Frequently Asked Questions About Comparing Lists

How do I compare two Excel or Google Sheets columns?

Select your first column in Excel or Sheets, copy it, paste into List A. Do the same for the second column into List B. The delimiter is already set to Line Break so you're good to go.

I have two email lists - how do I find the overlap?

Paste the first list into A, second into B. Turn off Case Sensitive (email addresses are case-insensitive). The In Both box gives you the shared addresses.

Who doesn't follow me back on Instagram?

Use the Instagram template to load some sample data. Then paste the accounts you follow into List A and your actual followers into List B. Whatever shows up in Only in A is who isn't following you back.

Step-by-Step Guide: How to find Instagram non-followers (no login required)

Does this send my data anywhere?

No. Everything runs locally in your browser tab. I don't have a server receiving your lists - there's nothing to send.

My data is comma-separated, not one item per line - will that work?

Yes. Open the Delimiter dropdown and switch it to Comma. Same goes for tab-separated, semicolons, pipes, or whatever weird format your data is in - there's even a Custom Regex option if you need something specific.