Phone Number Validator & E.164 Formatter - Single or Batch

Enter Phone Number

Country

Phone Number

Loading phone validation library..

Try These Examples

How to Validate a Phone Number

Select the Country

Choose the country from the dropdown. Numbers typed without a + are read with that country's dialing rules, prefix patterns and length requirements. Numbers that start with + are matched to their own country automatically.
Enter the Phone Number

Type the number in the Single tab, with or without the country code. Spaces, dashes, dots and parentheses are fine; the tool ignores them.
Review the Validation Result

The result shows whether the number is valid, possibly valid, or invalid, plus the number type such as mobile, fixed line, VoIP or toll-free, and the detected country.
Copy the Formatted Output

Copy the E.164, international, national or Tel URI format. E.164 is the format most SMS and voice APIs expect; the national format suits local display.
Check a List in the Batch Tab

Open the Batch tab, paste one number per line and select Validate All. The table shows each number's E.164 form, whether it is valid and its country. Copy All Valid E.164 copies only the valid numbers, one per line.

Common Use Cases

Form Input Validation

Verify phone numbers entered in signup forms, checkout pages, and contact forms before storing them. Reject invalid formats early to prevent delivery failures for SMS notifications and two-factor authentication codes.

Database Cleanup and Normalization

Paste a column of phone numbers into the Batch tab and convert them all to E.164. One consistent format makes records searchable, removes duplicates caused by formatting differences like (415) 555-2671 and +14155552671, and matches what messaging APIs such as Twilio and Vonage expect.

International SMS and Voice Campaigns

Before sending bulk SMS or making automated calls, validate each number against country-specific rules. Identify phone types to route mobile numbers to SMS channels and fixed lines to voice channels.

CRM Data Quality Auditing

Audit customer records for invalid or incorrectly formatted phone numbers. Detect the country of origin, normalize formatting, and flag numbers that cannot receive SMS for better campaign targeting.

Why use Phone Number Validator?

Check phone numbers before you store them or send an SMS. The Single tab validates one number against its country's numbering plan, detects the number type (mobile, fixed line, VoIP, toll-free) and gives you E.164, international, national and Tel URI formats. The Batch tab takes a list, one number per line, and returns each number in E.164 with its country, so you can copy every valid number in one click.

Phone Number Validator checks whether a phone number is valid for its country and converts it into standard formats. It runs in your browser with libphonenumber-js, a JavaScript library built on the numbering-plan metadata of Google's libphonenumber, so it applies each country's rules for number length, prefixes and formatting. The numbers you type are not uploaded.

The Single tab detects the number type (mobile, fixed line, VoIP, toll-free, premium rate) and the country, and gives you the number in E.164, international, national and Tel URI formats. The Batch tab takes a list with one number per line and returns each one in E.164 with its country, plus a count of valid and invalid numbers. E.164 is the format most SMS and voice APIs expect. When you build a signup form, pair this tool with the Email Validator to check both contact fields, or use the Regex Tester to write a pattern for a specific number format.

For teams that handle international customer data, one phone format prevents duplicate records and failed deliveries. Clean messy text first with the Data Sanitizer, then run the numbers through the Batch tab. To check the domain behind a contact's email address, use DNS Lookup.

How it compares

Phone number checkers fall into two groups: format validators, which check a number against the country's numbering plan, and carrier lookup services, which ask the network whether a line is active. This tool is a format validator. It needs no account or API key, and the numbers you enter are checked in your browser rather than uploaded. Carrier lookup services usually charge per request and need an account, but they can confirm that a number is in service and name its carrier, which a format check cannot do.

Developers who need validation inside an application can install libphonenumber-js or Google's libphonenumber directly. This page gives the same library's results without any setup, and the Batch tab covers the common one-off job of normalizing a list before an import.

Tips for Phone Number Validation

Store phone numbers in E.164 format (+ followed by the country code and number) so they work with APIs and across regions.
Include the country code when validating numbers from international users, or set the default country, so national formats are not read with the wrong country's rules.
Use the phone type to route messages: SMS to mobile numbers, voice calls to fixed lines.
Validation checks numbering-plan rules, not whether a number is in service. Use a carrier lookup service when you need to know that a line is active.
E.164 never includes the trunk prefix, such as the leading 0 used in many countries. Select the country and the tool drops it for you.

Frequently Asked Questions

What is E.164 format?

E.164 is the ITU-T standard for international phone numbers: a plus sign, the country calling code (1 to 3 digits), then the subscriber number, with no spaces or punctuation and at most 15 digits in total. Example: +14155552671. Most SMS and voice APIs expect numbers in this format.

How accurate is the validation?

The validator checks number length, prefixes and format rules for each country using libphonenumber-js. It tells you whether a number fits the country's numbering plan, but it cannot tell whether the number is in service or assigned to someone.

Can I validate a list of phone numbers at once?

Yes. Open the Batch tab, choose a default country, paste one number per line and select Validate All. The table shows each number's E.164 form, whether it is valid and its country, and Copy All Valid E.164 copies only the valid numbers, one per line.

How do I convert a local number to E.164?

Select the country from the dropdown and enter the number as you would dial it locally. The tool adds the country code and drops the trunk prefix, such as the leading 0 used in many countries, and shows the E.164 result. A number that already starts with + is matched to its own country.

What phone types can be detected?

For valid numbers the tool reports the type: mobile, fixed line, fixed line or mobile, toll-free, premium rate, shared cost, VoIP, personal number, pager, UAN or voicemail. Detection is based on the number ranges defined for each country; where a country does not separate the ranges, the type shows as fixed line or mobile.

What does 'Possibly Valid' mean?

A 'Possibly Valid' result means the number has a plausible length for the country, but it does not match a range the numbering plan marks as valid. It may be unassigned or mistyped, so check it before relying on it.

What is the difference between E.164 and international format?

E.164 is the compact machine form with no spaces or dashes, for example +14155552671. International format adds spacing for people to read, for example +1 415 555 2671, following the ITU-T E.123 display conventions. Store E.164, and show the international format.

Does E.164 include extensions?

No. E.164 covers only the dialable number: a plus sign followed by digits. Extensions, pauses and tone sequences are not part of it, so keep an extension in a separate field next to the E.164 number.

Is this tool free and private?

Yes. It is free, needs no signup, and validation runs in your browser with libphonenumber-js, so the numbers you type or paste are not uploaded.

Is there an API for phone number formatting?

Yes. The REST endpoint phone-format and the MCP tool phone_format validate a number and return it in E.164, international and national form with its country. They use the same libphonenumber-js metadata as this page, so a number gets the same valid or invalid answer in both places. Give the country as an ISO code (such as GB) or a calling code (such as 44) for numbers without a +. The API does not report the number type (mobile, fixed line); the Single tab does. An API call sends the number to FindUtils over TLS; it is not stored or logged.

Run it from code

$ curl -X POST \
  api.findutils.com/api/tools/phone-format/execute \
  -d '{"phone":"+1 415-555-0132"}'

$ claude mcp add findutils \
  --transport http https://mcp.findutils.com/
# then call findutils:phone_format

API reference Add to Claude

Phone Number Validator