Free Duplicate Lead Checker Find Duplicate Emails Instantly
Duplicate contacts waste sending volume and make prospects receive the same cold email twice a fast route to spam complaints. Paste your list and this checker shows every repeated email and how many times it appears.
How this check works
- 01
Emails are normalized (trimmed, lowercased) before comparison, so case variants count as duplicates.
- 02
Each address is counted; anything appearing more than once is listed with its count.
- 03
A summary shows total rows, unique emails, and the dedupe savings.
How to fix common problems
Duplicates across merged lists
Duplicates usually appear after merging exports from Apollo, LinkedIn, and events. Always dedupe the merged file, not each source.
Same person, two companies
If someone changed jobs, keep the newest record and their current company domain stale addresses bounce.
Example
2,500 rows → 2,310 unique. The 190 duplicates would have burned 8% of your monthly sending volume on repeat touches.
FAQ
- Does it catch jane@acme.com vs Jane@acme.com?
- Yes comparison is case-insensitive after normalization.
- Can I check duplicates across two lists?
- Paste both lists together; any address appearing 2+ times across the combined paste is reported.
- Is my data stored?
- No. The check runs entirely in your browser.
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