NumTrue checks if a phone number is actually live, dead, or disposable, using real HLR/MNP carrier lookups, not regex format-checking. Most "validators" just check format and call a disconnected number valid; NumTrue queries the real carrier network for live/dead status, ported carrier, and disposable/burner detection. Bulk CSV upload or REST API. Pay-as-you-go credits, no subscription, never expire. From $9 for 1,000 lookups, 10 free to start.