Regex to Match International Phone Numbers

This regex validates international phone numbers in various formats. Here is the token-by-token breakdown:

^ — Anchors the match at the start of the string.

+? — Matches an optional plus sign at the beginning, commonly used before the country code in international dialing format.

\d{1,3} — Matches one to three digits for the country code. Country codes range from one digit (e.g., 1 for US) to three digits (e.g., 358 for Finland).

[\s.-]? — Matches an optional separator (whitespace, dot, or hyphen) after the country code.

(? — Matches an optional opening parenthesis, as some formats enclose the area code in parentheses.

\d{1,4} — Matches one to four digits for the area or city code. Different countries have varying area code lengths.

)? — Matches an optional closing parenthesis.

[\s.-]? — Matches an optional separator.

\d{1,4} — Matches one to four digits for the next part of the phone number.

[\s.-]? — Matches another optional separator.

\d{1,9} — Matches one to nine digits for the remaining part of the number. This generous range accommodates the varying lengths of phone numbers across different countries.

$ — Anchors the match at the end.

International phone numbers vary greatly in length and format. This pattern is intentionally flexible to accommodate numbers from different countries. For strict validation of a specific country, a country-specific pattern is recommended.