WhatsApp Number Validator

Check any phone number for E.164 format, country code, and expected length - before you send, call, or build a chat link.

Check a number
Pick a country and type just the national number - we'll prepend the dial code. Or paste a full international number starting with +.
Result
Enter a number and click Validate to see the result.

What this tool checks

This is a basic validator: it verifies a number's format rather than whether the number is actually active on a network or registered on WhatsApp. That distinction matters - real "is this number on WhatsApp?" checks require a paid provider API. For most use cases a format check catches the vast majority of mistakes.

Checks performed (all local)

  • Digits only - non-digit characters are stripped and flagged.
  • E.164 length - total digits must be between 7 and 15 (the ITU E.164 standard).
  • Country code match - longest-prefix match against 240+ dial codes.
  • Subscriber length - checks the national part fits the expected length for the detected country.
  • Trunk prefix (leading 0) - warns if you included a domestic trunk prefix that needs stripping.
  • Canonical formats - outputs E.164 and a wa.me-ready string.

What this tool does not do

  • No HLR / MNP lookup - it won't tell you the carrier or whether the number has been ported.
  • No "is this on WhatsApp?" check - those require an authorised WhatsApp Business API partner.
  • No SMS pings - we never contact the number.

Privacy

Validation runs entirely in your browser. The number is not sent to us, logged, or cached anywhere except the current tab.

Frequently Asked Questions

Can this tell me if the number is registered on WhatsApp?
No. WhatsApp does not expose a public registration-check endpoint. Use the Test on WhatsApp button: an opened chat means registered, an invalid-URL error means not.
What is E.164 format?
E.164 is the ITU-T international telephone standard: + country code + national subscriber number, no spaces, capped at 15 digits. Required by WhatsApp, SMS gateways, and carriers.
Why is the leading zero a problem?
Many countries prefix domestic numbers with 0 for internal dialling. That 0 must be dropped when prepending the country code internationally, otherwise carriers reject the number.
Why do some numbers pass even though they look wrong?
Subscriber-length ranges are rules of thumb. Some numbers are shorter or longer for special services. The tool warns rather than rejects when the format is valid but outside common ranges.
Can I paste a list of numbers?
This tool validates one number at a time. For bulk validation, script against a full library like libphonenumber-js offline.
Is the number sent anywhere?
No. The check runs entirely in the browser with a bundled country-code dataset. Nothing is uploaded or logged.