Sinch Verification API vs SuperTokens

Sinch Verification API provides multi-factor authentication and phone-number verification for app sign-up, login, and password resets. Developers can use one-time passwords, password-free verification, or other account checks through backend REST APIs and native Android and iOS SDKs. Verification methods include SMS, voice calls, flash calls, and data verification. Sinch describes multilingual service across devices and platforms, with fallback options for delivery, conversion, and price, supported by more than 600 direct tier-1 operator connections. Its Dashboard shows verification results and delivery and conversion metrics in real time. Named identity integrations include Okta and Auth0, while developer guides also cover ForgeRock and SAP. Data Verification requires mobile data to be enabled, and Sinch advises contacting an account manager to use it. For SDK requests from untrusted mobile devices, Sinch recommends Public Authentication and says verification callbacks should validate requests to help prevent fraud. The service has free access and trial credit through Sinch Build. Pay-as-you-go verification is billed per request; SMS pricing varies by country and operator, while flash calls have a fixed price per attempt.

SuperTokens is an open-source authentication provider for developers adding sign-in and session management to applications. It supports email and password, passwordless email or SMS codes, magic links, social login, and passkeys. Enterprise options include tenant-specific login methods, separate user pools, and enterprise SSO. Developers can adapt the prebuilt interface and add logic before or after API operations with hooks and overrides. Backend SDKs communicate with SuperTokens Core; frontend SDKs call authentication routes exposed by the application backend. Core can be self-hosted, with open-source features free at any scale and no MAU limit. A managed Cloud plan is also available, free under 5K MAUs and then $0.02 per MAU. Other paid or sales-led features include multi-tenancy, cross-domain unified login, machine-to-machine authentication, availability zones with uptime SLAs, and Attack Protection Suite. That suite can detect risky authentication activity and prompt extra verification or block attempts. Integrations include Next.js, NestJS, GraphQL, Capacitor, AWS Lambda, Vercel, Hasura, and Supabase. SuperTokens says it is SOC 2 compliant and describes more than 100 controls and tests.