List Difference Checker —
See Exactly What's Missing
Paste two lists and instantly find what's missing from List A, what's extra in List B, and what's shared. Free, private, no sign-up needed.
Live preview — one-time comparison only. Open the full tool for export, fuzzy match, dedup, and save history.
What Does a List Difference Checker Do?
A list difference checker takes two lists and produces three outputs:
- Missing from B — items in List A that are absent from List B
- Extra in B — items in List B that are not in List A
- Shared by both — the intersection of the two lists
This replaces the manual process of eyeballing two lists or writing VLOOKUP formulas in Excel — and it works instantly on any size list, in your browser, with zero setup.
Key Features
- Instant resultsDifferences appear the moment you click Compare.
- 100% privateAll processing is local. No data is ever sent to a server.
- Fuzzy matchingFind near-matches to catch typos and spelling variations.
- DeduplicateOptionally remove duplicates within each list before comparing.
- Export CSV / JSONDownload any result section for further analysis.
- Paste from ExcelPaste tab-separated data directly from spreadsheets.
When to Use a List Difference Checker
Email list hygiene: Check which subscribers are on your master list but missing from your CRM export — or vice versa.
Inventory reconciliation: Compare your expected product SKU list against what's actually in your warehouse system to find discrepancies.
Data migration: After migrating records from one system to another, check which records didn't transfer correctly.
Compliance checks: Compare an approved vendor list against invoices paid this quarter to find unapproved vendors.
Academic research: Compare participant IDs across two datasets to find which subjects are missing data in one collection.
Frequently Asked Questions
What is a list difference checker?
A list difference checker compares two lists and identifies which items are unique to each list and which are shared. Paste your two lists above for instant results.
How do I find the difference between two lists?
Paste List A and List B into the tool above. Results appear instantly — "Only in A", "Only in B", and "Common to both".
Can I find what's missing from a list?
Yes. The "Only in A" section shows everything in List A that's missing from List B, and "Only in B" shows the reverse.
Does it handle duplicates?
Yes. Enable the deduplication option to remove duplicate entries within each list before comparison.
What formats are supported?
Newline-separated, comma-separated, and semicolon-separated lists all work. Excel and Google Sheets paste is supported.