What is this CSV deduplicate tool?
A free, browser-based tool that removes duplicate rows from a CSV. Deduplicate by all columns (a row is a duplicate only when every cell matches an earlier row) or by a single key column such as email or ID. The first occurrence is kept and later duplicates are dropped, and you see the before/after row counts at a glance. It's ideal for cleaning lead lists and CRM exports before importing them elsewhere. Everything runs locally in your browser, so your data is never uploaded.
How to use it
- Upload a CSV file or paste it into the box on the left.
- Choose to deduplicate by all columns, or by a single key column.
- Check the before/after row counts to see how many duplicates were removed.
- Copy the result or download it as a new CSV.
Common use cases
- De-duplicating a lead list on the email column before an import.
- Removing fully identical rows produced by merging several exports.
- Collapsing repeated customer IDs to one row each.