Free CSV Lead Cleaner Clean & Deduplicate Lead Lists
Paste raw CSV or a column of emails and get back a cleaned list: trimmed, lowercased emails, invalid rows removed, duplicates stripped. The cleaned output appears in a box you can copy straight into Clay, Apollo, or your sending tool.
How this check works
- 01
Each line is split on commas; the first column that looks like an email is extracted.
- 02
Emails are trimmed and lowercased; rows without a syntactically valid email are dropped.
- 03
Duplicates are removed keeping the first occurrence.
- 04
The cleaned list is rendered for one-click copy. Nothing is uploaded.
How to fix common problems
Mixed casing and spaces
Jane@Acme.com and jane@acme.com are the same mailbox but different strings tools treat them as two contacts unless normalized first.
Hidden invalid rows
Trailing spaces, missing dots, and stray semicolons from Excel exports cause hard bounces. Drop them before upload, not after.
Example
Input: ' John Smith , John@ACME.com ' and 'john@acme.com' on two lines → output keeps a single normalized 'john@acme.com' row.
FAQ
- Does it keep other CSV columns?
- This cleaner focuses on producing a clean, deduplicated email column. For full-column cleaning, export the email column, clean it here, then re-join in your sheet.
- Is there a row limit?
- No hard limit lists of 50,000+ rows clean in a few seconds since everything runs locally in your browser.
- Does cleaning also verify emails?
- No. Cleaning fixes formatting and duplicates. Run the Email List Validator afterward to check domain-level deliverability.
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