Regex Tester & Validator

Matches US-style phone numbers in a wide variety of formats, including optional country codes (e.g., +1), flexible separators such as dashes, dots, spaces, and parentheses around the area code, plus an optional extension (e.g., x1234). It validates the standard 3-3-4 digit grouping of area code, exchange, and subscriber number. With global and multiline flags enabled, it is well-suited for extracting all phone numbers from multiline text, capturing the full number in group 1 and the extension digits in group 2.