Auth0 vs GetOTP

Auth0 (an Okta company) is an identity platform providing hosted login, social and enterprise SSO, and adaptive multi-factor authentication for web, mobile, and API-first applications. Both its Authentication API and Management API are secured exclusively through OAuth 2.0 / OIDC bearer tokens issued via a tenant's /oauth/token endpoint — there is no standalone API-key scheme. It bills per monthly active user, with a free tier for small projects and paid Essentials/Professional/Enterprise plans for scale.

GetOTP is a multichannel one-time-password verification API covering SMS, voice call, Telegram, and Viber, with built-in retry and delivery-fallback logic so teams skip building their own OTP pipeline. Requests are authenticated with an X-OTP-Key header against api.otp.dev/v1/verifications, and responses are plain JSON with account_id/message_id tracking fields. New accounts get 100 free verification requests before billing switches to pay-per-verification.