How to dedupe marketing leads by email
- Step 1Export your lead list — Download leads from your CRM, form tool, ad platform, or spreadsheet as CSV.
- Step 2Drop the CSV into Deduplicator — The file is parsed locally in your browser.
- Step 3Choose the unique key — Select Email, Phone, CRM ID, or whichever column should define one lead.
- Step 4Download the deduped file — Review the duplicate count and export a clean CSV for import or outreach.
Frequently asked questions
Can I dedupe by email only?+
Yes. Choose the Email column as the unique key and the tool removes later rows with the same email.
What happens to rows with blank email?+
Rows with empty keys are kept so you can review them manually instead of losing data.
Are lead details uploaded?+
No. Names, emails, and phone numbers stay in your browser.
Privacy first
Processing runs locally in your browser with PapaParse. No file is uploaded — only metadata counters are saved for signed-in dashboard stats.