Free tool

Free Phone Number Validator

Check any number against E.164 and country formatting rules instantly — see exactly why a number fails, not just that it did.

Enter a number, with or without formatting, to validate it.

Why validate numbers

A bad number is cheap to catch, expensive to ship.

Most number problems are a missing country code, a leftover trunk prefix, or a dropped digit — none of it needs a live network query. Just a check against rules that don't change: E.164 structure and each country's expected length.

Signup & form validation
Reject malformed numbers at the point of entry instead of discovering them later.
Fewer failed SMS / OTP sends
A number that fails E.164 checks will fail delivery too — catch it before you pay to send it.
Cleaner CRM & marketing lists
Bulk-import numbers with confidence that the format, not just the presence of digits, is checked.
Lower fraud & chargeback risk
Obviously malformed numbers are a cheap early signal in a broader fraud-screening flow.
How it works

Rules-based today, live status on demand.

The free validator runs entirely in your browser, checking the "+", dialing code, E.164 length range, trunk prefix and per-country digit range — every failure reason is shown.

What it can't tell you is whether a well-formed number is actually reachable right now — that needs a live carrier query via the Lookup API or a Rozper account.

+ prefix
Country code
E.164 length
No trunk 0
Valid
Common failure reasons
Missing country code
The number has no "+" or recognizable dialing code, so it can't be routed internationally.
Wrong total length
Too few or too many digits for any valid E.164 number (outside the 8–15 digit range).
Leftover trunk prefix
A local "0" left in front of the subscriber number after the country code was added.
Unusual length for the country
Digit count doesn't match what that country's numbering plan typically expects.
Cleaning a whole list?

Validate numbers in bulk.

The Lookup API validates and checks live status for thousands of numbers per call — ideal for CRM cleanup and pre-send SMS scrubbing.

Talk to sales
FAQ

Questions, answered.

Live validation & status

Validate with confidence, at scale.

Start a free trial to access the Lookup API, or book a demo to see it on your own data.