Regex Tester & Validator

Matches international telephone numbers by allowing an optional leading '+' and 1-4 digit country code, an optional parenthesized area code, and multiple digit groups separated by hyphens, dots, or spaces. A lookahead constrains the total character count to 10-15, roughly aligning with E.164 phone number length guidelines. Useful for validating or extracting phone numbers from user input in international forms and contact datasets.