The generator allows you to create fictitious (or sometimes even real) phone numbers in several different formats. The generated numbers can be used to test systems or to protect your privacy (e.g., creating an account that requires a number).
Generated phone numbers can be used to test applications or forms. This is useful for finding bugs or validating code functionality, especially when the field also contains an input mask.
The generated numbers can be useful in automated testing environments (e.g. xUnit, NUnit, etc.) or automated calling (e.g. Twilio).