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Spam and botnet prevention

Block botnets and bulk account creation with phone verification for new users: helping to prevent spam more effectively.

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Phone verification prevents bulk account creation and eradicates spam more effectively than captchas or social logins.

Better user experience

Minimises personal information sharing (compared to using social network registrations) and enables a nearly frictionless registration experience for mobile users.


Every user with a phone has a unique identifier, enabling you to grow the audience for your application with confidence.

How spam and botnet prevention works

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1. The user enters their phone number

As part of the registration process, the app asks the user to enter his/her number.
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2. Vonage APIs Verify sends a code

Verify sends a text message containing an authentication code to that number. If the user is on a landline, Vonage APIs automatically make a phone call and delivers the code via text-to-speech.

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3. The user enters the authentication code

The user receives the message and enters the authentication code in the installer screen.
Pictogram of four stars and an check mark indicating successful verification.

4. Vonage APIs Verify validates the code

Behind the scenes, Verify confirms that the user has entered the correct code. If so, the app installation can continue.
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5. And weeds out the botnets and spammers

If the code is incorrect, Verify can prompt the user to re-try. If the correct code is never entered, your app can cancel the installation process.

Programmable elements used in this solution

Why choose Vonage APIs for spam and botnet prevention?

Local compliance solved

Vonage APIs compliance engine, with built-in knowledge of global numbering plans and local regulations, makes sure that messages are delivered and don’t get caught by carrier filters. For example, the sender ID and message templates adapt automatically to guarantee delivery in every country and carrier so you don’t need to write different code for each destination.

Verify only valid numbers

Verify validates that a user’s number is current and valid — even before trying to send a message to that number — eliminating outbound messages to bogus numbers or numbers that are not in service.

Manage the contingencies automatically

Verify detects if an authentication code has not been entered and automatically sends a second code if necessary. In addition, it detects landline numbers automatically and uses Vonage APIs text-to-speech engine to deliver validation messages as voice calls instead of SMS.

Predictable charges, billed only on conversion

Verify aligns Vonage APIs goals with your goals by charging a flat fee for verifications — and charging only for successful verifications. Capitalising on Vonage APIs experience in delivering more than 3.5 billion phone verifications worldwide, Verify has been optimised to exceed benchmark conversion rates. In addition, information about all your verifications is accessible from a dashboard.

The lowest latency

Verify takes advantage of Vonage APIs direct-to-carrier connections and adaptive routing engine to achieve the rapid delivery of verification codes anywhere in the world without delay. Retries and voice failover are automatic if a recipient does not enter the correct code on the first attempt. Additionally, the Vonage APIs Verify SDK for mobile apps provides a customisable user experience framework for improved verification success.

Related solutions

Private SMS communication Connect your users via text message privately.
Call Tracking Track call metadata for lead generation and marketing campaigns.
Passwordless Authentication Replace static passwords with single-use codes sent over SMS, voice or push.

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