Twilio - Brings voice and messaging to your web and mobile applications.
RealValidito - Phone Validator | Free Phone Number Validation & Phone Number Lookup Service | Realvalidito
Plivo - Plivo simplifies your customer engagement.
Numverify - Global phone number validation and lookup API
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Clearout Phone - Phone Number Validation - Accuracy Guaranteed, GDPR Compliant, Abuse Phone Number Checker, Real-Time API 99.999% Uptime - Free Trial With 100 Credits!