Clean a whole list of phone numbers at once
Before any SMS campaign, CRM import or call list, phone numbers need to be validated and put into one consistent format. Doing it by hand is slow, and pasting the list into a chatbot is worse: it quietly truncates long lists, formats numbers inconsistently, and can drop or invent entries. This free tool validates and formats every number exactly, using Google's libphonenumber library, right in your browser.
What you get for each number
- Valid or invalid: whether it can be a real phone number, clearly flagged.
- E.164 format: the international standard (+14155552671) that SMS, CRM and telephony systems expect.
- National format: how it is written locally.
- Country and line type: which country it belongs to, and whether it looks like a mobile or fixed line.
How to use it
- Paste your numbers, one per line or comma-separated.
- Pick a default country so numbers without a country code (like 0555 123 456) are understood correctly.
- Validate, then copy the clean E.164 list or download the full results as a CSV.
Why deterministic beats a chatbot here
Phone formatting is a job that must be exact, not approximate. libphonenumber encodes the real numbering rules of every country, so validation and formatting are correct and repeatable for the whole list, however long. Duplicates are matched on the normalised number, so the same contact written two different ways is caught. And because it all runs in your browser, your customer contact data never leaves your device.