Why browser-side matters for phone lists

A phone list is personal data. Every bulk validator that processes your file on its servers becomes a data processor for your customers' numbers, with everything that implies. This tool takes the opposite approach: the validation rules (Google's libphonenumber, the same library most apps use) are downloaded to your browser once, and your list is processed on your own machine. There is no upload, no account, no log - and therefore no limit and no invoice.

What the flags mean

  • Valid: matches the country's official numbering plan (length, prefix, pattern) for a known type.
  • Possible: right length for the country, but no plan match - often a typo or an unassigned range.
  • Duplicate: the same number (after normalization to E.164) appears earlier in your list - the report tells you which row.
  • Fictional: the number sits in a range officially reserved by a regulator for film and TV (like 555-01XX in North America or Ofcom's 07700 900xxx). It will never connect. Full list of drama ranges →

Frequently Asked Questions

Is my phone list uploaded to your server?

No. Everything runs in your browser with Google's open-source libphonenumber rules. The numbers never leave your machine - we could not see them if we wanted to. That is why there is no limit and no price.

How many numbers can I validate at once?

Up to 1,000 per run (a browser performance limit, not a business one). For larger lists, split the file and run again - it stays free and private.

What does the validator check?

Country, length, prefix and pattern against the official numbering plans, the number type (mobile, landline, toll-free, VoIP), duplicates within your list, and known fictional film/TV ranges reserved by regulators. It does not probe whether a line is live - that requires carrier lookups that leak your data.