albertstill / libphonenumber-js

A simpler (and smaller) rewrite of Google Android's libphonenumber library

libphonenumber-js

A simpler and smaller rewrite of Google Android's libphonenumber library: easy phone number parsing and formatting in javascript.

See Demo

LibPhoneNumber

libphonenumber is a phone number formatting and parsing library released by Google, originally developed for (and currently used in) Google's Android mobile phone operating system. Implementing a rigorous phone number formatting and parsing library was crucial for the phone OS overall usability (back then, in the early 2000s, it was originally meant to be a phone after all, not just a social media device).

libphonenumber-js is a simplified pure javascript port of the original libphonenumber library (written in C++ and Java because those are the programming languages used in Android OS). While libphonenumber has an official javascript port which is being maintained by Google, it is tightly coupled to Google's closure javascript utility framework. It can still be compiled into one big bundle which weighs 530 kilobytes (330 kB code + 200 kB metadata) — quite a size for a phone number input component.

One part of me was curious about how all this phone number parsing and formatting machinery worked, and another part of me was curious if there was a way to reduce those 530 kilobytes to something more reasonable while also getting rid of all the unnecessary bulk and rewriting it all in pure javascript. The resulting library does everything a modern web application needs while maintaining a much smaller size of about 110 kilobytes.

Difference from Google's libphonenumber

• Much smaller footprint: 110 kilobytes (30 kB code + 80 kB sufficient metadata) vs the original Google's 530 kilobytes (330 kB code + 200 kB full metadata).
• Can search for phone numbers in text.
• Doesn't parse alphabetic phone numbers like 1-800-GOT-MILK.
• Doesn't use "carrier codes" when formatting numbers: "carrier codes" are only used in Colombia and Brazil and only when dialing within those countries from a mobile phone to a fixed line number.
• Doesn't parse or format special local-only phone numbers: emergency phone numbers like 911, "short codes", numbers starting with a *, etc.
• Doesn't parse or format phone numbers with "dial out codes". The "dial out codes" are the prefixes prepended in order to call to another country. E.g. an international phone number + ... would be called as 00 ... from Europe and 011 ... from the United States. The reason for not supporting "dial out codes" is that I don't see any use case where a user would input a phone number with a "dial out code" instead of using the + ... notation.

Installation

via npm

$ npm install libphonenumber-js --save

via yarn

$ yarn add libphonenumber-js

Usage

import { parseNumber, formatNumber, AsYouType } from 'libphonenumber-js'

parseNumber('8 (800) 555 35 35', 'RU')
// { country: 'RU', phone: '8005553535' }

formatNumber({ country: 'US', phone: '2133734253' }, 'International')
formatNumber('[phone]', 'International')
// '[phone]'

new AsYouType().input('[phone]')
// '[phone]'
new AsYouType('US').input('2133734')
// '(213) 373-4'

Country code definition

"Country code" means either a two-letter ISO country code (like US) or a special 001 country code used for non-geographical entities (as per Google's libphonenumber library). For example, [phone] phone number belongs to Russia so it has RU country code where as [phone] phone number could belong to any country so it has 001 country code.

API

parseNumber(text, [defaultCountry], [options])

Attempts to parse a valid phone number from text.

If defaultCountry is passed then it's gonna be the default country for parsing non-international phone numbers.

Returns { country, phone, ext } where

• country is a country code
• phone is a national (significant) number
• ext is a phone number extension

If the phone number supplied isn't valid then an empty object {} is returned.

parseNumber('[phone]') === { country: 'US', phone: '2133734253' }
parseNumber('[phone]', 'US') === { country: 'US', phone: '2133734253' }

// Parses phone number extensions.
parseNumber('[phone] ext. 123', 'US') === { country: 'US', phone: '2133734253', ext: '123' }

// Parses RFC 3966 phone number URIs.
parseNumber('tel:[phone];ext:123') === { country: 'RU', phone: '8005553535', ext: '123' }

Available options:

• defaultCountry : string — Same as defaultCountry argument.

• extended : boolean — If set to true then parseNumber() will attempt to parse "possible" phone numbers even if they're classified as "invalid". The result of "extended" parsing has shape { country, countryCallingCode, carrierCode, phone, ext, valid: boolean, possible: boolean }; some or all of these properties may be absent. The "extended" parsing is the default behaviour of the original Google's libphonenumber: it still returns parsed data even if the phone number being parsed is not considered valid (but is kinda "possible"). Though I don't know who might need such an advanced feature, still it has been requested and has been implemented.

Speaking of phone number extensions, I myself consider them obsolete and I'd just discard the extension part given we're in the 21st century. Still, some people asked for phone number extensions support so it has been added. But I personally think it's an unnecessary complication.

formatNumber(number, format, [options])

Formats a number into a string according to a format.

Available formats:

• National — e.g. [phone]
• International — e.g. [phone]
• E.164 — e.g. [phone]
• RFC3966 (the phone number URI) — e.g. tel:[phone];ext=123

Available options:

{
  formatExtension(number, extension) — Formats `number` and `extension` into a string.
                                       By default returns `${number} ext. ${extension}`.
}

The number argument must be either a parseNumber()d phone number object (to strip national prefix) or an E.164 phone number (e.g. [phone]). The parseNumber()d phone number object argument be expanded into two string arguments for those who prefer this kind of syntax.

formatNumber({ country: 'US', phone: '2133734253' }, 'International') === '[phone]'
formatNumber('2133734253', 'US', 'International') === '[phone]'
formatNumber('[phone]', 'International') === '[phone]'

// An example of an invalid phone number argument.
// (has not been parsed and therefore contains the `0` national prefix)
formatNumber('017212345678', 'DE', 'E.164') !== '[phone]'
// After proper parsing it works.
formatNumber(parseNumber('017212345678', 'DE'), 'E.164') === '[phone]'

// Formatting phone number extensions (except for E.164).
formatNumber({ country: 'US', phone: '2133734253', ext: '123' }, 'National') ===  '[phone] ext. 123'

class AsYouType(defaultCountry)

Creates a formatter for partially entered phone number. The defaultCountry is optional and, if specified, is gonna be the default country for formatting non-international phone numbers. The formatter instance has two methods:

• input(text) — Takes any text and appends it to the input. Returns the formatted phone number.
• reset() — Resets the input.

The formatter also has the following getters:

• country — Phone number country.
• getNationalNumber() — Returns the national number part of the phone number.
• template — The template used to format the phone number. Digits (and the + sign, if present) are denoted by x-es.

new AsYouType().input('[phone]') === '[phone]'
new AsYouType('US').input('2133734') === '(213) 373-4'

const asYouType = new AsYouType()
asYouType.input('[phone]') === '[phone]'
asYouType.country === 'US'
asYouType.getNationalNumber() === '2133734253'
asYouType.template === 'xx xxx xxx xxxx'

"As You Type" formatter was created by Google as part of their Android OS and therefore only works for numerical keyboard input, i.e. it can only accept digits (and a + sign in the start of an international number). When used on desktops where a user can input all kinds of punctuation (spaces, dashes, parens, etc) it simply ignores everything except digits. This solution is sufficient for all use cases except for phone number extensions which Google's "As You Type" formatter does not support. If your project requires phone number extensions input then use a separate input field for that.

findPhoneNumbers(text, [defaultCountry], [options])

Searches for phone numbers in a given text. This is a basic substitute for Google's original findNumbers() function (described below).

import { findPhoneNumbers } from 'libphonenumber-js'

findPhoneNumbers(`
  The number is [phone] and
  not [phone] as written
  in the document.
`, 'US')

// Outputs:
//
// [{
//   phone    : '8005553535',
//   country  : 'RU',
//   startsAt : 14,
//   endsAt   : 32
// },
// {
//   phone    : '2133734253',
//   country  : 'US',
//   startsAt : 41,
//   endsAt   : 55
// }]

If the text being searched in is big enough (say, a hundred thousand characters) then one can employ iterators to perform the search asynchronously (e.g. using requestIdleCallback or requestAnimationFrame to avoid freezing the user interface during the search).

ES6 iterator:

import { searchPhoneNumbers } from 'libphonenumber-js'

const text = `
  The number is [phone] and
  not [phone] as written
  in the document.
`

async function() {
  for (const number of searchPhoneNumbers(text, 'US')) {
    console.log(number)
    await new Promise(resolve => setTimeout(resolve, 0))
  }
  console.log('Finished')
}

Java-style iterator (for those still not using ES6):

import { PhoneNumberSearch } from 'libphonenumber-js'

const search = new PhoneNumberSearch(`
  The number is [phone] and
  not [phone] as written
  in the document.
`, {
  defaultCountry: 'US'
})

// Search cycle iteration.
const iteration = () => {
  if (search.hasNext()) {
    console.log(search.next())
    setTimeout(iteration, 0)
  } else {
    console.log('Finished')
  }
}

// Run the search.
iteration()

findNumbers(text, [defaultCountry], [options])

Searches for phone numbers in a given text. This is the Google's original implementation and it's not implemented in this library.

Although Google's javascript port doesn't support this functionality the Java and C++ ports do. I guess Google just doesn't need to crawl phone numbers on Node.js because they can afford to hire a Java/C++ developer to do that. Still, javascript nowadays is the most popular programming language given its simplicity and user-friendliness.

I made my take on porting Google's PhoneNumberMatcher.java into javascirpt and seems that it's doable. The overall syntax has mostly been ported but it's still quite far from finished and the code has not been tested, and I'm not searching for phone numbers in my projects, but if anyone needs that feature they could continue where I left off: see findNumbers.js, src/PhoneNumberMatcher.js and src/PhoneNumberMatcher.test.js. Such a person must also let others (including me) know that he's working on the feature to avoid any conflicts: a pull request must be created right away and code must be committed on a daily basis regardless of whether it works or not.

getNumberType(number, [defaultCountry])

Determines phone number type (fixed line, mobile, toll free, etc). This function will work if --extended (or relevant --types) metadata is available (see Metadata section of this document). The regular expressions used to differentiate between various phone number types consume a lot of space (two thirds of the total size of the --extended library build) therefore they're not included in the bundle by default.

The number argument can be either a result of the parseNumber() function call — { country, phone } — or a string possibly accompanied with defaultCountry.

getNumberType('9160151539', 'RU') === 'MOBILE'
getNumberType({ phone: '9160151539', country: 'RU' }) === 'MOBILE'

isValidNumber(number, [defaultCountry])

Checks if a phone number is valid.

The number argument can be either a result of the parseNumber() function call — { country, phone } — or a string possibly accompanied with defaultCountry.

isValidNumber('[phone]') === true
isValidNumber('+1-213-373') === false

isValidNumber('[phone]', 'US') === true
isValidNumber('(213) 37', 'US') === false

isValidNumber({ phone: '2133734253', country: 'US' }) === true

The difference between using parseNumber() and isValidNumber() for phone number validation is that isValidNumber() also checks the precise regular expressions of possible phone numbers for a country. For example, for Germany parseNumber('123456', 'DE') would return { country: 'DE', phone: '123456' } because this phone number matches the general phone number rules for Germany. But, if the metadata is compiled with --extended (or relevant --types) flag (see below) and the precise regular expressions for possible phone numbers are included in the metadata then isValidNumber() is gonna use those precise regular expressions for validation and isValid('123456', 'DE') will return false because the phone number 123456 doesn't actually exist in Germany.

So, the general phone number rules for a country are mainly for phone number formatting: they dictate how different phone numbers (matching those general regular expressions) should be formatted. And parseNumber() uses only those general regular expressions (as per the reference Google's libphonenumber implementation) to perform basic phone number validation. isValidNumber(), on the other hand, is all about validation, so it digs deeper into precise regular expressions (if they're included in metadata) for possible phone numbers for a given country. And that's the difference between them: parseNumber() parses phone numbers and loosely validates them while isValidNumber() validates phone number precisely (provided the precise regular expressions are included in metadata).

By default those precise regular expressions aren't included in metadata because that would cause metadata to grow twice in its size (the complete metadata size is about 145 kilobytes while the default reduced metadata size is about 77 kilobytes). If anyone needs to use (or generate) custom metadata then it's quite easy to do so: follow the instructions provided in the Customizing metadata section of this document.

Using phone number validation feature

I personally wouldn't rely on strict phone number validation too much because it might get outdated:

• First, new phone number rules are added to Google's libphonenumber library after they have already been implemented in real life (which introduces a delay).

• Then those new rules from Google's libphonenumber are updated automatically in this library (the scheduled update script introduces a small delay of 1 day, unless it malfunctions).

• And then there's still the web application itself using this library and until a developer installs libphonenumber-js@latest manually and redeploys the web application it's gonna use the old (potentially outdated) phone number validation rules which could result in losing customers with perfectly valid (but brand new) phone numbers if a website form is too strict about validating user's input.

Phone number validation rules are constantly changing for --extended rules and are fairly static for "general" ones. Still imagine a web application (e.g. a promosite or a "personal website") being deployed once and then running for years without any maintenance.

getCountryCallingCode(country)

There have been requests for a function returning a country calling code by country code.

getCountryCallingCode('RU') === '7'
getCountryCallingCode('IL') === '972'

Metadata

Metadata is generated from Google's original PhoneNumberMetadata.xml by transforming XML into JSON and removing unnecessary fields.

Currently I have a script set up monitoring changes to PhoneNumberMetadata.xml in Google's repo and automatically releasing new versions of this library when metadata in Google's repo gets updated. So this library's metadata is supposed to be up-to-date. Still, in case the automatic metadata update script malfunctions some day, anyone can request metadata update via a Pull Request here on GitHub:

• Fork this repo
• npm install
• npm run metadata:update:branch
• Submit a Pull Request to this repo from the update-metadata branch of your fork

npm run metadata:update:branch command creates a new update-metadata branch, downloads the new PhoneNumberMetadata.xml into the project folder replacing the old one, generates JSON metadata out of the XML one, checks if the metadata has changed, runs the tests, commits the new metadata and pushes the commit to the remote update-metadata branch of your fork.

Alternatively, a developer may wish to update metadata urgently, without waiting for a pull request approval. In this case just perform the steps described in the Customizing metadata section of this document.

React

There's also a React component utilizing this library: react-phone-number-input

Examples

For those asking for phone number examples for use in <input placeholder/>s there's examples.mobile.json.

Bug reporting

When reporting an issue one must also provide a link to Google's libphonenumber demo page illustrating the expected behaviour. This includes validation, parsing, formatting and "as you type" formatting. For example, for an Australian number 438 331 999 Google's demo outputs four sections — "Parsing Result", "Validation Results", "Formatting Results" and "AsYouTypeFormatter Results". In a bug report, first describe the observed libphonenumber-js demo result and then Google's demo result (with a link to it) which must differ from the observed libphonenumber-js demo result. If the observed libphonenumber-js demo result is the same as Google's demo result and you don't agree with Google's demo result then create an issue in Google's repo.

Phone number validation bugs should only be reported if they appear when using custom metadata functions fed with metadata.full.json because by default all functions in this library use the reduced metadata set which results in looser validation than the original Google libphonenumber's. The demo page also uses the reduced metadata set and therefore its validation is also looser than the original Google libphonenumber's.

TypeScript

TypeScript support for this library is entirely community-driven. I myself don't use TypeScript. Send your pull requests.

Webpack

If you're using Webpack 1 (which you most likely are) then make sure that

• You have json-loader set up for *.json files in Webpack configuration (Webpack 2 has json-loader set up by default)
• json-loader doesn't exclude /node_modules/
• If you override resolve.extensions in Webpack configuration then make sure .json extension is present in the list

Webpack 2 sets up json-loader by default so there's no need for any special configuration. So better upgrade to Webpack 2 instead.

Standalone

For those who aren't using bundlers for some reason there's a way to build a standalone version of the library

• git clone https://github.com/catamphetamine/libphonenumber-js.git
• npm install
• npm run browser-build
• See the bundle folder for libphonenumber-js.min.js

<script src="/scripts/libphonenumber-js.min.js"></script>
<script>
  alert(new libphonenumber.AsYouType('US').input('213-373-4253'))
</script>

Customizing metadata

This library comes prepackaged with three flavours of metadata

• metadata.full.json — contains everything, including all regular expressions for precise phone number validation and getting phone number type, but weighs 145 kilobytes.
• metadata.min.json — (default) the minimal one, doesn't contain regular expressions for precise phone number validation and getting phone number type, weighs 80 kilobytes.
• metadata.mobile.json — contains regular expressions for precise mobile phone number validation, weighs 105 kilobytes.

Furthermore, if only a specific set of countries is needed in a project, and a developer really wants to reduce the resulting bundle size, say, by 50 kilobytes (even when including all regular expressions for precise phone number validation and getting phone number type), then he can generate such custom metadata and pass it as an extra argument to this library's functions.

First, add metadata generation script to your project's package.json

{
  "scripts": {
    "libphonenumber-metadata": "libphonenumber-generate-metadata metadata.min.json --countries RU,DE --extended",
  }
}

And then run it like npm run libphonenumber-metadata.

The arguments are

• The first argument is the output metadata file path.
• --countries argument is a comma-separated list of the countries included (if --countries is omitted then all countries are included).
• --extended argument may be passed to include all regular expressions for precise phone number validation and getting phone number type, which increases the precision of phone number validation but at the same time it will enlarge the resulting metadata size approximately twice.
• --types ... argument may be passed instead of --extended to only include the precise phone number type regular expressions for a specific set of phone number types (a comma-separated list, e.g. --types mobile,fixed_line). The complete list of phone number types.

Then use the generated metadata.min.json with the exported "custom" functions.

In ES6 that would be

import {
  parseNumber,
  formatNumber,
  isValidNumber,
  getNumberType,
  AsYouType
} from 'libphonenumber-js/custom'

import metadata from 'libphonenumber-js/metadata.full.json'

parseNumber('[phone]', metadata)
formatNumber({ phone: '8005553535', country: 'RU' }, metadata)
isValidNumber('[phone]', metadata)
getNumberType('[phone]', metadata)
new AsYouType('RU', metadata).input('[phone]')

or

import {
  parse as parseCustom,
  format as formatCustom,
  isValidNumber as isValidNumberCustom,
  getNumberType as getNumberTypeCustom,
  AsYouType as AsYouTypeCustom
} from 'libphonenumber-js/custom'

export const parse = (...args) => parseCustom(...args, metadata)
export const format = (...args) => formatCustom(...args, metadata)
export const isValidNumber = (...args) => isValidNumberCustom(...args, metadata)
export const getNumberType = (...args) => getNumberTypeCustom(...args, metadata)

export class AsYouType extends AsYouTypeCustom {
  constructor(country) {
    super(country, metadata)
  }
}

And for Common.js environment that would be

var custom = require('libphonenumber-js/custom')
var metadata = require(libphonenumber-js/metadata.full.json)

exports.parseNumber = function parseNumber() {
  var parameters = Array.prototype.slice.call(arguments)
  parameters.push(metadata)
  return custom.parseNumber.apply(this, parameters)
}

exports.formatNumber = function formatNumber() {
  var parameters = Array.prototype.slice.call(arguments)
  parameters.push(metadata)
  return custom.formatNumber.apply(this, parameters)
}

exports.isValidNumber = function isValidNumber() {
  var parameters = Array.prototype.slice.call(arguments)
  parameters.push(metadata)
  return custom.isValidNumber.apply(this, parameters)
}

exports.getNumberType = function isValidNumber() {
  var parameters = Array.prototype.slice.call(arguments)
  parameters.push(metadata)
  return custom.getNumberType.apply(this, parameters)
}

exports.AsYouType = function AsYouType(country) {
  custom.AsYouType.call(this, country, metadata)
}

exports.AsYouType.prototype = Object.create(custom.AsYouType.prototype, {})
exports.AsYouType.prototype.constructor = exports.AsYouType

Metadata should be re-generated each time the project is being deployed because Google constantly updates their metadata.

Contributing

After cloning this repo, ensure dependencies are installed by running:

npm install

This module is written in ES6 and uses Babel for ES5 transpilation. Widely consumable JavaScript can be produced by running:

npm run build

Once npm run build has run, you may import or require() directly from node.

After developing, the full test suite can be evaluated by running:

npm test

When you're ready to test your new functionality on a real project, you can run

npm pack

It will build, test and then create a .tgz archive which you can then install in your project folder

npm install [module name with version].tar.gz

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License

MIT