Regex pattern
Email Regex — free online tester
A practical email-validation regex that catches the 99% case without choking on every RFC edge case.
The pattern
[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}/giHow it works
Email addresses follow a deceptively complex spec (RFC 5322). A full-coverage regex is hundreds of characters long and still gets corner cases wrong. In practice, the pattern below catches every email format you'll see in production input — local part with letters, digits, dots, underscores, percent signs, plus, hyphens; @ separator; domain with one or more labels; TLD of 2 or more letters.
When to use it
- ▸Frontend form validation before sending data to the server
- ▸Extracting email addresses from log files or scraped text
- ▸Cleaning up CSV / spreadsheet imports
- ▸Quick sanity checks in scripts and one-off shell commands
Tip
Use this as a first-pass filter, then verify the address actually exists by sending a confirmation email. Regex can't tell you the inbox is real.
Try it on this input
Contact us at [email protected] or [email protected]. Customers wrote in: [email protected], [email protected], [email protected] Bad ones: not.an.email, [email protected], @nodomain.org, plain text only
What this pattern doesn't catch
- ⚠Won't flag valid but unusual addresses with quoted local parts ("john doe"@example.com)
- ⚠Doesn't enforce IDN (internationalised) domains like 北京.中国
- ⚠Treats single-letter TLDs as invalid (none exist today, but the spec allows them)
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Match ISO 8601 dates (YYYY-MM-DD) and optionally times in any text — the format JSON APIs, databases, and logs use.
IPv4 Regex
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UUID Regex
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Credit Card Regex
Match credit-card numbers from major networks (Visa, Mastercard, Amex, Discover) for extraction or redaction.
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