This tool uses the Google libphonenumber library to validate phone numbers. The library is used by Google in its products and is considered the most accurate phone number validation (it is an open-source library that is usually updated by contributors from around the world).

Validator features:

• Validation according to international standards
• Support for more than 200 countries
• Various output formats (international, national, E.164, URI)
• Number type detection (mobile, landline, etc.)
• Checking whether the number can exist

Supported formats:

• International: +420 123 456 789
• National: 123 456 789
• E.164: +420123456789

Note: The validator checks the format and possible existence of a number, but does not guarantee that the number is currently active or assigned. The sources are usually national numbering plans, which determine how formats are theoretically used in a given country.