Any user, anywhere

Phone verification made simple. We're so confident in our ability to deliver messages, you only pay for successful authentication. Available as an API and SDK.

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Test drive the code

Try the code below to see just how simple our Verify API is.

curl '' 
-d api_key=API_KEY 
-d api_secret=API_SECRET 
-d number=YOUR_NUMBER 
-d brand=MyApp  

curl '' 
-d api_key=API_KEY 
-d api_secret=API_SECRET 
-d request_id=REQUEST_ID 
-d code=CODE 

/* where REQUEST_ID is the value returned to you  
 * from the first request and CODE is the code  
 * received on the phone at YOUR_NUMBER 

Docs and Libraries

Don’t take our word for it. Give our API or SDK codes a go to see how easily they integrate. Prefer to cut to the chase? View the docs or browse the pre-built community libraries

View docs Explore libraries

Plug and play

Just integrate our API or SDK into your app and let Verify do the rest. Discover how we consistently deliver one of the highest verification rates in the industry.

  • Less code, less complexity

    Phone verification shouldn’t be complex. Just give us a number and we’ll take care of everything - generate the code, localize, use the fastest channel, fall back if and when needed.

  • Never settle for average

    Verify has fast delivery, intelligent failover and selects the optimal channel for reaching your user. What’s more, Verify complies with changing carrier and country regulations so messages won’t get filtered out.

  • Pay for success

    Why should failure cost you anything? With Verify you only pay per successful verification. What’s more, it works on a flat fee basis, regardless of where users are based. And you can monitor costs in real time.

API & SDK-wide features

Boost verification success

Deliver verification codes over the fastest routes determined by Verify in real-time. Verify automatically resends a code and failsover to voice if needed.

Block spam and fraud

Verify detects and blocks virtual, Premium, and Toll-Free numbers that are used for spam and fraud. PIN codes are generated using the industry standard RFC6238 algorithm – and expire within minutes.

Global compliance

Verify ensures your messages are compliant and abstracts the complexity of monitoring global carrier and country regulations.

Adapted to regional preferences

Languages and voice accents are adapted to regional preferences to maximize verification success.

Mobiles and landline verification

Simply send Verify a phone number. Verify detects the number type and selects the appropriate channel - SMS or voice.

Whitelabeled and customizable

Customize message templates, pre-record voice calls, and configure the time between retries to deliver the user experience you desire.

*These are patented Vonage features. View patent information.

SDK-specific features

Discover the capablities of the SDK version of Verify

Verify with just one call

Save design and development resources with a customizable UI that is pre-integrated with verification workflows and has log-in management across devices.

Subscribe and save money

SDK uses push notifications so subscribers can verify users multiple times with no additional cost.

More security

Combine phone numbers with unique mobile device IDs to detect SIM swaps. Automatically logout users after set time and enforce re-authentication.

Use Cases

Password-less login

Replace passwords with single use codes sent over SMS, voice or push. Phone number identities let you connect your users from their contacts.

Prevent bulk registration

Verify unique phone numbers to prevent bots, spammers, and card testers more effectively than captchas or email verification.

2-factor authentication

Add a second factor to authenticate users without hardware costs or complex integration. Ensure global reach from day one.

Password reset

Securely reset passwords by confirming users’ ownership of their phone number. Resolve speedily and eliminate help desk costs.

Step-up authentication

Enforce out-of-band authentication on high-value transactions or when risk score crosses a threshold and eliminate manual reviews.

Tiered user verification

Balance user acquisition with compliance by phone verifying lower tier customers instead of onerous id verification for all users.


Pay only for what you use, nothing more

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