Phone number to international format converter

What is this international phone number converter?

A free, browser-based tool that converts a list of phone numbers into the international format — '+' and the country code, e.g. +81 90 1234 5678. Paste one number per line; it strips spaces, hyphens, and parentheses and rewrites each number with the right country code. Numbers worldwide are supported, and numbers without a country code are read using the default country you select. Rows it can't parse are flagged in red. Everything runs locally in your browser, so your data is never uploaded.

How to use it

1. Paste your phone numbers (one per line) into the box on the left.
2. Pick the default country, used to read numbers written without a country code.
3. Read the international numbers on the right — invalid rows are highlighted in red — then copy each row, copy all, or download the result.

Common use cases

• Preparing a contact list for an SMS or voice service that requires the international format.
• Unifying domestic numbers from several countries into one consistent +country-code style.
• Spotting malformed numbers before they break an import or campaign send.

Other list tools

• Phone number normalizer
• Date normalizer
• Full/half-width normalizer
• Email validator