What this tool does
This validator checks phone numbers against Google's libphonenumber library, the same open-source library used by Android and many other apps and services. It verifies the number structure, identifies the country, detects whether it's a mobile or landline number, and formats it in standard international formats.
Phone number formats explained
E.164 format
E.164 is the international standard for phone numbers. It starts with a + sign, followed by the country code and the subscriber number with no spaces or dashes. Example: +4989123456. This is the format used by most APIs, CRMs, and telephony systems.
International format
The international format adds spaces for readability while keeping the country code. Example: +49 89 123456. This is what you'd use when writing a phone number that might be dialed from another country.
National format
The national format is how you'd dial the number within the same country. In Germany, it includes a leading zero for the area code: 089 123456.
RFC 3966 (tel: URI)
This format is used in HTML links so browsers and phones can make a call when someone clicks the link: tel:+49-89-123456.
Why phone number validation matters
Invalid phone numbers in your CRM or contact list mean failed calls, bounced SMS messages, and wasted time. Validating numbers before storing them catches typos and formatting errors early. If you're importing contacts or processing form submissions, running numbers through a validator first saves headaches later.
