Remove duplicates from your CSV — and prove what changed
Upload a messy list and get back one clean file. DedupeCSV finds exact and fuzzy duplicates, lets you review each group before anything is merged, and hands you an audit file that shows every removed row and why.
Clean a CSV now — free See a worked example
No signup needed for small files · Free plan: 1,000 rows per file · Your files are deleted after 24 hours
More than exact matches
“Jon Smith” and “John Smith”, the same email with a +tag, a phone number with or without the country code — plain duplicate removers miss all of these. Fuzzy matching with adjustable strictness catches them, and every group shows its similarity score and the reason it matched.
Review before anything is lost
Duplicates are grouped into clusters. You pick the row to keep, split out rows that are not really duplicates, and merge the rest with rules like “most complete wins” plus automatic fill-in of empty fields. Nothing disappears silently.
An audit file, every time
You download three files: the clean list, an audit CSV listing every removed or merged row with its cluster and reason, and a summary. Row counts always add up, so you can hand the result to your team — or your CRM — with confidence.
How it works
- Upload a CSV, TSV or XLSX file (or paste the text). We detect the delimiter and encoding and show you a profile of every column.
- Choose what makes two rows “the same” — email, phone, name, or a combination. The likely key columns are pre-selected for you.
- Review the clusters, adjust the strictness if needed, and confirm the merges.
- Download the clean file, the audit file, and the summary. On paid plans, save the whole setup as a recipe and rerun it on next month’s list in one click.
Built for repeat cleanups
Marketing and sales ops teams merge fresh exports every month. Nonprofits clean donor and member lists every year. Saved recipes, two-file reconciliation against your master list, and files of up to 200,000 rows are what paid plans are for — see pricing.
Your data stays yours
Files are processed on our server so big lists actually finish. Uploads are stored only so you can review and download your results, and they are deleted automatically after 24 hours — sooner if you delete them yourself. Details in the privacy policy.