This libphonenumber parser shows what the library makes of any phone number, in plain words.

A possible number has the right length, and a valid one also sits in a range the country hands out.

These eight numbers show where the two checks part ways. Every answer below came from the library when this page was built.

Each field the parser returns answers one narrow question.

The names are libphonenumber-js's. The Java original and its ports use the same ideas under longer names (isValidNumber, getNumberType).

phone.country

The two-letter country the number belongs to, or nothing when one calling code covers several and the digits do not say which.

phone.countryCallingCode

The digits after the + that pick the country: 1, 44, 91.

phone.nationalNumber

The number without its calling code and without the trunk 0 the country dials at home.

phone.isPossible()

The length fits some number in that country. Nothing more is checked.

phone.isValid()

The length and the leading digits fit a range the country hands out.

phone.getType()

Which kind of range the digits fall in: mobile, landline, toll-free and so on.

phone.getPossibleCountries()

Every country that shares the calling code and could own the number.

phone.ext

An extension typed after the number, such as ext. 204.

The same parse in four languages

// npm install libphonenumber-js
import { parsePhoneNumberFromString } from "libphonenumber-js/max";

const phone = parsePhoneNumberFromString("+1 201 555 0123", "US");
phone?.isValid();          // valid for the numbering plan
phone?.getType();          // MOBILE, FIXED_LINE, ...
phone?.format("E.164");    // what to store

# pip install phonenumbers
import phonenumbers
from phonenumbers import PhoneNumberFormat, number_type

p = phonenumbers.parse("+1 201 555 0123", "US")
phonenumbers.is_valid_number(p)
number_type(p)  # 1 = MOBILE, 0 = FIXED_LINE, ...
phonenumbers.format_number(p, PhoneNumberFormat.E164)

// com.googlecode.libphonenumber:libphonenumber
PhoneNumberUtil util = PhoneNumberUtil.getInstance();
Phonenumber.PhoneNumber p = util.parse("+1 201 555 0123", "US");
util.isValidNumber(p);
util.getNumberType(p);   // MOBILE, FIXED_LINE, ...
util.format(p, PhoneNumberUtil.PhoneNumberFormat.E164);

// composer require giggsey/libphonenumber-for-php
use libphonenumber\PhoneNumberUtil;
use libphonenumber\PhoneNumberFormat;

$util = PhoneNumberUtil::getInstance();
$p = $util->parse('+1 201 555 0123', 'US');
$util->isValidNumber($p);
$util->getNumberType($p);
$util->format($p, PhoneNumberFormat::E164);

The smallest libphonenumber-js metadata gives no number type for most countries.

We ran every country's example mobile number, and two broken copies of each, through all three metadata sets of libphonenumber-js 1.13.7: 735 numbers from 245 countries.

libphonenumber has a port for nearly every language, and they all share Google's metadata.

The answers come from the metadata, not the code, so two ports on the same metadata release agree. When they disagree, one of them is behind on updates.

libphonenumber knows the numbering plan, but it cannot see the live line.

The library works from a file of ranges, so three questions are out of its reach. Each one has a free tool.

These free tools pick up where the library stops.