Compare Two Lists Online
Paste two lists and instantly find what's missing, what's extra, what overlaps, or merge them into one. Free, private, and runs entirely in your browser.
Paste your lists to get started
Add items to List A and List B, then pick an operation to see results instantly. Use the delimiter selector to match your input format.
How It Works
Paste your lists
Paste your data into List A and List B. Works with emails, IDs, names, SKUs, or any text.
Select your delimiter
Choose how your items are separated — newline, comma, space, tab, semicolon, or pipe. The tool adapts instantly.
Pick an operation
Click A − B for missing items, B − A for extras, A ∩ B for overlap, or A ∪ B to merge both lists.
Copy your results
Copy to clipboard in your preferred format (one-per-line, CSV, or JSON) or download as a file.
Why DataMinus
One Answer, Not Five Panels
Other tools dump five result sets at once. DataMinus shows you exactly the one thing you're looking for — toggle between operations with a single click.
See Where Results Come From
Result items are highlighted directly in your original lists. No more copying and searching — you can visually see which items matched or missed.
Instant Stats That Tell the Story
Before you even look at results, the stats bar tells you: how many items, how much overlap, and what percentage. The summary you'd normally compute by hand.
Your Data Stays on Your Device
No servers, no uploads, no tracking. Everything runs in your browser. Close the tab and it's gone. Auto-save uses only your browser's local storage.
Any Delimiter, Any Format
Paste comma-separated values, space-separated words, tab-delimited exports, or pipe-separated data. Choose your delimiter and DataMinus handles the rest — no reformatting needed.
Common Use Cases
Email Lists
Compare CRM exports, find missing subscribers, or clean suppression lists.
IDs & SKUs
Reconcile order IDs, product SKUs, or database keys between two systems.
Missing Records
Find which records from one export are missing from another.
Find Overlap
Identify shared items between two datasets, lists, or exports.
Merge Lists
Combine two lists into one deduplicated master list.
Frequently Asked Questions
- How do I compare two lists online?
- Paste your first list into the List A panel and your second list into the List B panel. Then click one of the operation buttons: A − B to find items only in List A, B − A for items only in List B, or A ∩ B to find items that appear in both lists. Results appear instantly.
- Is my data safe? Do you store my lists?
- Your data never leaves your browser. DataMinus runs entirely on your device using JavaScript. No data is uploaded to any server, no cookies track your activity, and nothing is stored remotely. Close the tab and your data is gone (unless you have auto-save enabled, which uses your browser's local storage only).
- What does A − B mean?
- A − B (also called "set difference") shows items that are present in List A but missing from List B. For example, if List A has [apple, banana, cherry] and List B has [banana, date], then A − B gives you [apple, cherry] — the items that are in A but not in B.
- Can I compare lists of emails or IDs?
- Yes. DataMinus works with any text-based list — emails, user IDs, product SKUs, URLs, keywords, names, or anything else. Paste your data and select the matching delimiter (newline, comma, space, tab, semicolon, or pipe). For emails, we recommend turning off "Case sensitive" since email addresses are case-insensitive.
- What is the maximum list size I can compare?
- DataMinus handles very large lists efficiently. Lists with 10,000+ items are processed in milliseconds using JavaScript Set operations. For lists exceeding 50,000 items, performance may vary depending on your device, but it will still work without freezing.
- How is this different from VLOOKUP in Excel?
- VLOOKUP requires writing formulas, setting up helper columns, and understanding complex syntax. DataMinus gives you the same result in 3 seconds: paste both lists, click an operation, and copy the result. No formulas, no setup, no chance of #N/A errors.
- What delimiters are supported?
- DataMinus supports six input delimiters: newline (one item per line), comma, space, tab, semicolon, and pipe ( | ). Choose the delimiter that matches your data format using the dropdown. This means you can paste comma-separated values, space-separated words, or tab-separated exports directly without reformatting.
- What does A ∪ B (union) do?
- A ∪ B combines both lists into a single list of all unique items, with duplicates removed. If List A has [apple, banana] and List B has [banana, cherry], the union is [apple, banana, cherry]. This is useful when you want to merge two lists into one master list without duplicates.