Compare Two Lists
Easily compare two lists to find differences, similarities, and unique items. A powerful tool for data analysis and list management.
Click to select a TXT file
Click to select a TXT file
Only in list A
Only in list B
In both lists
Results:
How to compare two lists online
- 1
Paste or upload your lists
Put the first list in the List A box and the second list in the List B box, one item per line. You can also upload a .txt file for each list.
- 2
Fix the format if needed
If your items are separated by commas, tabs or semicolons, use Replace to turn the separator into a line break (\n). Regular expressions are supported.
- 3
Choose your options
Tick Case insensitive if "Apple" and "apple" should count as the same item. For very large lists, Reduce output shows only the first 100 items of each result group.
- 4
Click Compare Lists
You instantly get three groups: items only in list A, items only in list B, and items in both lists. Copy any group or download it as a .txt file.
Understanding the results
Every comparison (or "list diff") splits your data into three groups. Here is a simple example:
List A
apple banana cherry grape
List B
banana grape mango orange
Only in list A
apple, cherry
Items in list A that are missing from list B – for example, accounts you follow that don't follow you back, or customers who did not reorder.
Only in list B
mango, orange
Items in list B that are not in list A – such as new sign-ups, new followers, or products added since your last export.
In both lists
banana, grape
The intersection of the two lists: matching items that exist in both, such as mutual followers or customers found in both databases.
Empty lines are ignored, and each result group lists every item only once, even if it appears several times in your input.
Why use this list diff tool
100% private
Your lists are processed in your browser. Nothing is uploaded to a server or stored, so it is safe for email addresses, customer data and other sensitive lists.
Free, no sign-up
No account, no installation and no usage limits. Open the page and start comparing.
Fast with large lists
The comparison runs in linear time, so even lists with tens of thousands of lines finish almost instantly.
Flexible input
Paste text or upload TXT files, convert comma-, tab- or semicolon-separated values into lines, and choose case-sensitive or case-insensitive matching.
Export results
Download each result group as a plain-text file and paste it into Excel, Google Sheets or any other app.
Available in 5 languages
Use the tool in English, Chinese, German, Japanese or Korean.
What can you compare?
Instagram followers vs following
Export both lists from Instagram, put following in List A and followers in List B. "Only in list A" shows who doesn't follow you back.
Open the Instagram checker →Two Excel or Google Sheets columns
Copy two columns from a spreadsheet and compare them without writing VLOOKUP, COUNTIF or MATCH formulas.
Compare lists in Excel →Email and customer lists
Find subscribers missing from your CRM, remove unsubscribed addresses from a mailing list, or check which customers appear in both systems.
Inventory, SKUs and orders
Reconcile stock lists with sales records, or find product IDs that went missing after an import.
IDs, keywords and domains
Check two lists of user IDs, keywords, domains or file names before writing a script.
Compare lists in Python →Research data
Compare gene lists, sample IDs or survey respondents to find the overlap and differences between two datasets.
Online tool vs Excel vs Python
There are several ways to compare two lists. Pick the one that fits your task:
| Method | Best for | What you need |
|---|---|---|
| Online tool (this page) | One-off comparisons and quick checks, no technical skills needed | A browser – results in seconds |
| Excel / Google Sheets | Data already in a spreadsheet that you want to highlight or keep updating | Formulas such as COUNTIF or VLOOKUP, or conditional formatting |
| Python | Repeated or automated comparisons and very large files | Basic programming with sets or collections.Counter |
Step-by-step guides: Compare lists in Excel · Compare lists in Python
Frequently Asked Questions
Find answers to common questions about our list comparison tool
Paste the first list into List A and the second into List B, one item per line, then click Compare Lists. The tool shows the items only in list A, only in list B, and in both lists.
Yes. All processing happens locally in your browser. Your lists are never uploaded to our servers, stored or shared.
By default, yes: "ABC" and "abc" are different items. Select Case insensitive to treat them as the same; the results are then shown in lower case.
Use Replace: enter , in the first field and \n (line break) in the second, then click Replace Selected. This also works for tabs (\t), semicolons, pipes and other separators. Advanced: regular expressions and capture groups ($1) are supported.
Empty lines are ignored, and each result group lists every item only once. To count how many times each item repeats in a single list, use the List Deduplication tool.
Yes. Items must match exactly, so "apple" and "apple " (with a trailing space) are treated as different. If your data contains stray spaces, clean them up before comparing.
There is no fixed limit – it depends on your device's memory, and lists with tens of thousands of lines work smoothly. For uploaded files, the text box shows only the first 100 lines, but the whole file is compared.
Download your followers and following lists from Instagram's Download your information page, paste following into List A and followers into List B, then compare. Only in list A shows the accounts that don't follow you back. See the step-by-step guide.