What is this phone number normalizer?
A free, browser-based tool that converts a list of phone numbers written in mixed styles into one consistent format. Paste one number per line — it strips spaces, hyphens, and parentheses and rewrites every number to your chosen format: International (+81 90 1234 5678), National (090-1234-5678), International without symbols (+819012345678), or a tel: link. Numbers worldwide are supported; numbers without a country code are read using the default country you select. Rows it can't parse are flagged in red so nothing slips through silently. Everything runs locally in your browser, so your data is never uploaded.
How to use it
- Paste your phone numbers (one per line) into the box on the left.
- Pick the default country (used for numbers without a country code) and choose the output format — each format shows a live preview.
- Read the normalized list on the right — invalid rows are highlighted in red — then copy each row, copy all, or download the result.
Common use cases
- Cleaning a phone column exported from a CRM or spreadsheet before importing it elsewhere.
- Converting domestic numbers to E.164 for an SMS or voice API that requires it.
- Spotting malformed numbers that would break a later import or campaign send.
