Handle common phone formats like (555) 123-4567, 555-123-4567, and +14155551234 without hand-writing every variation.
Smart Regex Builder
Regex for Phone Number Validation
Generate and test regex for phone number validation — US formats, international E.164 numbers, and separator styles — in a browser-based regex builder.
Test real phone formats — dashes, spaces, parentheses, country codes — before you copy the regex.
- Save regex patterns, flags, and test strings in one browser workspace
- Resume validation work later with matching and failing examples intact
- Share the exact regex workspace when you want review or handoff
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Browser-native
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Regex studio
Generate regex from examples
Generate a regex builder workflow from sample strings, explain regex clearly, and use the built-in regex tester in the same workspace.
Example strings
alex@example.com maya@company.io test.user@site.dev
/^[^\s@]+@[^\s@]+\.[^\s@]+$/i^Start of string
[^\s@]+One or more non-space characters before the @
@An @ symbol
\.[^\s@]+A dot and a domain segment
$End of string
Why it helps
Why generate phone number regex with a builder
Test matching and failing samples so the pattern accepts real numbers and rejects malformed ones.
Read a plain-English explanation of each token so the validation rule stays maintainable.
How to use it
How to build a phone number regex
1 Paste phone numbers that should match — include every format your form accepts.
2 Add malformed samples that should fail, then review the generated pattern and explanation.
3 Copy the regex into JavaScript, Python, or backend validation code.
Quick tips
Phone number regex tips
A permissive baseline like ^\+?[\d\s().-]{7,20}$ catches most real-world input; tighten it per country only if you must.
For international numbers, validate the E.164 shape ^\+[1-9]\d{1,14}$ and let a phone library handle country rules.
Normalize input (strip spaces, dots, and dashes) before validating to keep the pattern simple.
FAQ
Phone number regex questions
Can this generate regex for US phone numbers?
Yes. Add samples like (555) 123-4567 and 555-123-4567 and the builder generates a pattern you can test against matching and failing cases.
Can I validate international phone numbers with regex?
Yes, for shape checks. The E.164 pattern ^\+[1-9]\d{1,14}$ validates international number structure; carrier-level validity needs a phone library or verification step.
Should regex be my only phone validation?
No. Use regex to catch obvious format errors early, then rely on SMS or call verification to prove a number is real and reachable.
Can I test the phone regex before copying it?
Yes. The regex builder shows live match results for both valid and invalid samples before you copy the pattern.
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