Email Validator
Upload a .txt or .csv file of email addresses and instantly see which entries are correctly formatted and which are not. Each invalid email is flagged with a plain-English reason (e.g., missing @-sign, invalid domain). A summary counts total, valid, and invalid addresses – perfect for quick list hygiene, all processing happens locally in your browser.
How to Use
- 1Click the upload area and select a .txt or .csv file containing one email address per line.
- 2Click "Validate Emails" – the tool reads the file and checks every entry.
- 3Review the results: the summary shows total, valid, and invalid counts, and the invalid list explains exactly why each address failed.
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Frequently Asked Questions
Will my email list be uploaded anywhere?
No. The file is read entirely in your browser – nothing leaves your device.
What email patterns are considered invalid?
The validator uses industry-standard rules (RFC-like checks) including mandatory @-sign, a valid domain structure, no spaces, and reasonable length limits. If an address doesn't match these rules, you'll see a specific reason.
Can I validate a file with thousands of addresses?
Yes, the tool processes the file line-by-line in memory. Performance is excellent for typical list sizes; however, extremely large files (>50 000 lines) may take a few seconds, but will still complete in-browser.