Email Validator
Validate single or multiple email addresses instantly. All processing happens locally in your browser — your data is never uploaded.
Privacy: All email addresses are validated entirely within your browser using local JavaScript. No data is sent to our servers or any third-party service.
About the Email Validator
What is an Email Validator?
An Email Validator is a tool that checks whether an email address is correctly formatted according to established internet standards (RFC 5321 / RFC 5322). It catches common typos and structural problems — like a missing @ symbol, invalid characters, or a malformed domain — before you send a message or submit a form.
Format validation vs. email verification
It's important to understand the difference between these two concepts:
- Format validation checks that an email address follows the correct syntax — does it have a local part, an
@, and a valid domain? This is what this tool does. - Email verification (deliverability checking) actually attempts to contact the mail server to confirm the mailbox exists. This requires network requests and cannot be done purely in a browser without privacy implications.
A valid format does not guarantee the mailbox exists or belongs to a real person.
What makes an email address valid?
- Must contain exactly one
@symbol. - The local part (before
@) must not be empty, exceed 64 characters, or start/end with a dot. - The domain (after
@) must contain at least one dot and a valid TLD of at least 2 letters. - No consecutive dots, invalid characters, or hyphens at the start or end of domain labels.
Common validation errors
- Missing @:
johnatexample.com - Multiple @:
john@@example.com - Missing domain:
john@ - No domain extension:
john@example - Consecutive dots:
john..doe@example.com - Invalid characters:
john space@example.com
How to use this tool
- Single Email: Type or paste one email address and click Validate (or press Enter).
- Bulk Emails: Paste a list of emails (one per line) and click Validate Emails. Or upload a
.txt,.csv, or.xlsxfile — the tool will auto-detect the Email column. - After bulk validation, use Copy Valid / Copy Invalid to extract specific groups, or Export CSV to download the full report.
Privacy & security
This tool processes all email addresses entirely within your browser using local JavaScript. No data is transmitted to our servers or any third-party service. This makes it safe to use for validating sensitive customer email lists, HR data, or any other private information without privacy concerns.