OTP Authentication Your Users Can Trust
OTP Authentication made simple with one API call. Generate, deliver, and verify OTPs across SMS , WhatsApp , and Voice with sub-5-second delivery, built-in fraud protection, and intelligent retry handling—so you never have to build verification logic from scratch.
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+91Trusted by 8,500+ businesses across India for secure OTP authentication
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End-to-End OTP Verification Service — No Infrastructure to Build
OTP (One-Time Password) authentication verifies that a user genuinely owns the phone number they're signing up or logging in with. It's the backbone of login, signup, password reset, and payment confirmation flows.
Most teams end up building this twice — once for delivery, and again for generation, expiry, retry limits, and verification. TextSpeed's OTP Authentication API handles the entire flow end-to-end, so you integrate once and never touch it again.
Everything You Need for a Reliable OTP Gateway
Built for secure OTP authentication and verification flows that need to work every time not just most of the time.
Instant Delivery
Sub-5-second OTP delivery via SMS, with automatic multi gateway failover so a slow route never costs you a user.
Built-In Verify API
Send the OTP and verify the code the user enters, both handled by TextSpeed. No need to store, hash, or expire codes yourself.
Multi-Channel Fallback
If SMS delivery is delayed, automatically retry over WhatsApp or Voice call, configurable per use case.
Fraud & Abuse Protection
Built-in rate limiting, retry caps, and suspicious-pattern detection to stop OTP-bombing and SIM-swap abuse before it hits your bill.
DLT Compliant by Default
OTP templates are pre-mapped to compliant DLT templates, so verification codes are never dropped by operator filters.
Configurable Expiry & Retry Rules
Set OTP validity window, max attempts, and resend cooldowns per app or per flow, enforced server-side, not in your code.
Drop-In SDKs
REST API plus SDKs for Node.js, PHP, Python and more, a working OTP flow in under 30 minutes.
Real-Time Analytics
Track delivery rate, verification success rate, and abuse attempts per app from a single dashboard.
4 Steps — From Trigger to Fast OTP Delivery
Manage the complete OTP Verification process with just two API calls. Our OTP Authentication API ensures fast, secure delivery with automatic fallback for uninterrupted User Authentication.
Trigger OTP Send
Call /otp/send with the user's phone number; TextSpeed generates and delivers the code instantly.
User Enters the Code
In your app's UI, as usual, you only collect what the user types.
Verify with One Call
Send the code to /otp/verify; get a simple valid / invalid / expired response back.
Auto-Retry on Failure
If delivery is delayed, TextSpeed automatically falls back to WhatsApp or Voice based on your config.
Deploy Your OTP Verification API in Minutes
Launch your OTP API Integration with just two endpoints for OTP Verification and authentication. Includes SDKs, webhooks, and a Postman collection for fast deployment with secure User Authentication.
Security & Compliance
DLT Compliant & Fraud-Proof by Default
Company_details and it's a prime target for abuse (OTP bombing, toll fraud). TextSpeed handles both without you lifting a finger.
- DLT-ready setup with pre-approved Entity, Sender ID, and OTP templates
- Strong rate-limit protection against misuse and suspicious activity
- Flexible control over OTP attempts, retries, and cooldown periods
- Secure OTP handling with no plaintext code storage in logs
The Difference That Matters at Scale with OTP Verification
A single OTP Authentication API for OTP Verification, SMS OTP Service, delivery, and verification. Enable Secure OTP Authentication, Mobile Number Verification, and Fast OTP Delivery with a reliable OTP Gateway built for enterprise-grade security.
One API, Not Three
Generation, delivery, and verification in a single integration, no stitching together separate services.
Multi-Channel Resilience
SMS-first with WhatsApp/Voice fallback keeps verification rates high even when one channel is congested.
Fraud Protection Built In
Stop OTP abuse without writing your own rate limiter, per-number and per-IP limits enforced server-side.
Scales with You
Same infrastructure for 100 signups/day or 10 million, no re-architecture, no renegotiation.
Flexible SMS OTP Service Pricing
Pay only for what you use with our Fast OTP Delivery solution. No setup fees or long-term commitments. Pricing is tailored based on usage, Transactional OTP SMS requirements, and your business needs.
Secure Onboarding Trusted by Developers
See how security-conscious teams protect logins and verify users using our secure two-factor authentication platform.
“Reliable & Effective Bulk SMS Services”Textspeed Technology has been a game-changer for our marketing campaigns. Their Bulk SMS service helped us reach our customers instantly, increasing engagement and sales. The reliability and delivery speed are exceptional!
“Complete Communication Solutions Under One Roof”We rely on Textspeed Technology for all our messaging needs, including Bulk SMS, WhatsApp API, and RCS services. Their seamless integration and efficient support have significantly enhanced our customer communication. Highly recommended!
“Trusted Bulk SMS Partner”Textspeed Technology has provided us with an outstanding Bulk SMS service that helps us communicate effectively with our stakeholders. Their system is fast, efficient, and easy to use!
“Powerful WhatsApp & SMS Marketing”Textspeed’s Bulk WhatsApp and SMS solutions have been instrumental in boosting our promotional campaigns. Their platform is user-friendly, and the customer support is top-notch!
“Seamless Bulk Messaging Solutions”Textspeed Technology’s Bulk SMS service has helped us streamline our sales communication. Their high delivery rates and intuitive platform make them a valuable partner for our business.
Don't Just Take Our Word For It . Ask AI
Learn how major AI systems rate Textspeed's OTP SMS delivery, secure login verification, and low-latency two-factor authentication features.
ChatGPT
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Claude
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AI responses are generated independently by each platform and may vary based on publicly available information.
OTP Authentication Gateway — Questions Answered
Everything you need to know about secure login OTPs, two-factor authentication, and SMS verification regulations.
You can configure automatic fallback to WhatsApp or a Voice call after a set delay, so delivery never fully depends on one channel.
Configurable per flow — default is 5 minutes, adjustable from your dashboard or the API request.
Codes are handled transiently for verification and are never written to plaintext logs.
Yes, resend cooldowns and max daily attempts per number are configurable to prevent abuse.
Yes, same as any transactional SMS. TextSpeed pre-registers a compliant OTP template so you can go live immediately.