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  4. GetOTP API
published

GetOTP API

The GetOTP API offers developers a straightforward method to send and validate OTPs via SMS, email, and WhatsApp, making it suitable for 2FA and phone verification needs.

Developed by OTP Dev

Live API
99.95%Uptime
200msLatency
150Stars
API KeyAuth
NoCredit Card
RESTStyle
v1Version

Reference

API Endpoints

Endpoints

Available routes, request structures, and code examples.

Creates one-time passwords for authentication flows

Endpoint URL
https://otp.dev/generate
Code Example
curl -X POST 'https://otp.dev/generate' \
  -H 'Authorization: Bearer YOUR_API_KEY'
Request Payload
{
  "expiry": 300,
  "length": 6
}
Expected Response
{
  "otp": "A3F9B7",
  "expires_at": "2023-07-18T15:30:00Z",
  "remaining_seconds": 300
}
Version:v1
Limit:50 OTPs/hour

Integration

Quick Start

cURL ExampleREST
curl -X GET "https://otp.dev/api/v1/generate"

Docs

Technical Documentation

What this API does

The GetOTP API is a robust solution designed to simplify the process of sending and validating one-time passwords (OTPs) across multiple channels including SMS, email, and WhatsApp. This API enables developers to quickly implement secure two-factor authentication (2FA) and phone verification mechanisms, enhancing the security of their applications.

How it works

Developers can send HTTP POST requests to the API to generate OTPs for users. The generated OTP can be sent through SMS, email, or WhatsApp, allowing for flexible integration. Validation is achieved by sending a subsequent request to verify the OTP entered by the user. All interactions utilize JSON format for data exchange.

Authentication

This API requires API key-based authentication. Developers must include their API key in the request headers to gain access to the endpoints.

Example usage

  • /sendOTP - Sends an OTP to the user's designated contact method (SMS, email, or WhatsApp).
  • /validateOTP - Validates the submitted OTP against the one generated and sent.

Limits

The service offers 500 free requests per month. Users must monitor their usage to stay within this limit.

Ideal use cases

  • Implementing two-factor authentication in web and mobile applications.
  • Verifying user identities during sign-up or login processes.
  • Enhancing security in sensitive transactions or account recoveries.

Examples

Real-World Applications

  • Enhancing login security with OTPs for user verification
  • Validating transactions through OTP confirmation
  • Integrating OTP workflows into multi-factor authentication systems
  • Phone number verification during user registration
  • Password reset verification

Evaluation

Advantages & Limitations

Advantages
  • ✓ Generous free tier with 500 free requests per month
  • ✓ Supports multiple delivery channels: SMS, email, WhatsApp
  • ✓ Easy RESTful API with JSON responses
  • ✓ Customizable OTP length and expiry settings
Limitations
  • ✗ Limited rate limit might be restrictive for high-volume apps
  • ✗ No official SDKs for some popular languages like Swift or Kotlin
  • ✗ Rate limits not well documented initially
  • ✗ No AI-powered features for fraud detection or anomaly analysis

Support

Frequently Asked Questions

Important Notice

Verify Before You Decide

Last verified · Apr 30, 2026

The details on this page — including pricing, features, and availability — are based on our last review and may not reflect the provider's current offering. Providers update their products frequently, sometimes without prior notice.

What may have changed

Pricing Plans
Features & Limits
Availability
Terms & Policies

Always visit the official provider website to confirm the latest pricing, terms, and feature availability before subscribing or integrating.

Check official site

External Resources

Documentation Official Website Pricing Details Postman Collection

API Specifications

v1
Pricing Model
Pay-as-you-go with volume discounts
Credit Card
Not Required
Response Formats
JSON
Supported Languages
7 Languages
SDK Support
JavaScript, Python, Java
Rate Limit

1000 requests per hour

Time to Hello World

Minutes

Free Tier

500 OTP requests per month with no credit card required

Best For

Startups and developers needing secure OTP verification with easy integration

Not Ideal For

Large enterprises requiring very high volume or advanced fraud detection features

Tags

#passwordless#otp#2fa#whatsapp#verification#authentication#email#sms#security

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