2Factor.in OTP API review
A phone verification API with SMS, voice fallback, and sandbox testing; paid plans start at ₹4,999/month.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
2Factor.in OTP API provides REST APIs and SDKs for phone verification and customer communications. It suits teams that need SMS OTP delivery and verification, with voice OTP available for fallback or voice authentication. The service runs in the cloud and offers a free Starter plan, so teams can explore its sandbox before choosing a paid subscription. Its wider communications platform also includes channels such as WhatsApp, RCS, email OTP, IVR, and outbound dialing.
The published plans distinguish testing from live messaging. Starter costs ₹0 per month and includes free test credits, an all-channel sandbox, REST API and SDKs, email support, and basic analytics. Growth costs ₹4,999 per month and includes ₹5,000 in messaging credits, all channels enabled, DLT and WABA onboarding, priority chat and email support, webhooks, real-time delivery receipts, and five team seats. The vendor also publishes usage-based SMS and OTP rates, so subscription price alone may not represent total messaging cost. Enterprise lists committed-volume discounts, dedicated routes and IPs, custom integrations, SSO, and a 99.99% uptime SLA.
Routing and delivery visibility are central strengths: unified multi-channel OTP routing, automatic route retry and failover, delivery webhooks, receipts, and analytics help teams track verification flows. API documentation includes examples for cURL, Node.js, Python, Go, and other languages. The supplied coverage is 190 countries, and the listed compliance standards are ISO 27001 and SOC 2. Support options vary by plan, with Enterprise listing 24×7 phone and Slack support and a dedicated account manager. Choose it if SMS and voice OTP, API access, and routing flexibility matter; teams seeking only a basic low-cost verification subscription should compare the recurring Growth fee and message usage costs with alternatives.
2Factor.in OTP API pros and cons
- Where it wins
- SMS OTP, voice authentication, and automatic fallback routing
- REST API, SDKs, sandbox testing, webhooks, and delivery receipts
- Free Starter plan; Growth adds ₹5,000 in messaging credits
- Where it doesn't
- Starter is limited to sandbox access and free test credits
- Growth begins at ₹4,999/month, apart from usage-based messaging rates
- Enterprise features such as dedicated routes and SSO are on the Enterprise plan
2Factor.in OTP API fact sheet, pricing and score →
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