A faster way to 2FA.

Pre-built with multi-channel failover. No experience required.

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Verification as simple as sending an SMS.

Focus on faster app development and let us take care of onboarding and authentication. Use a single API with ready-made logic to build and test PIN generation, delivery, and failover for more intelligent onboarding and authentication.

See the documentation
We need to verify a phone number
curl -X "POST" "https://api.nexmo.com/verify/json" \
-d "api_key=NEXMO_API_KEY" \
-d "api_secret=NEXMO_API_SECRET" \
-d "number=14155550100" \
-d "brand=MyApp" \
Get your API Key
Businesses Using Nexmo

Get smarter fail-safe, reliable delivery, and tailor-made messaging.

Intelligent Failover

Automatically resend PIN codes via voice (TTS) to customers through one API request without additional code.


Ensure optimum delivery by proactively re-routing messages around congestion—like GPS for your SMS.


Pay only for successful verifications, regardless of where users are based.
See All Features

Get everything you need with Nexmo Developer.

Read the docs and explore our libraries.

SDKs & Tools

Get up and running quickly in your language of choice.
View our API libraries on Github:
Plus get our command line tool.
Nexmo CLI


Provide feedback, gain, and share knowledge and find out where you can meet us in person via Slack, Stack Overflow, and Github.
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Per-conversion billing across the globe.

Verify a number for $0.0350 per successful verification.

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Let’s build something great together.

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