Glossary · Web & App Development
Auth0
Overview
What Auth0 is
Auth0 is identity-as-a-service: a hosted platform that manages who your users are and what they're allowed to do. Instead of writing and securing your own login system, you connect your app to Auth0 through its SDKs and APIs. It issues and validates secure tokens using open standards like OAuth 2.0 and OpenID Connect, and it's now part of Okta.
What it handles
Auth0 covers the full login lifecycle: username-password signup, social logins (Google, Apple, and others), single sign-on across multiple apps, and multi-factor authentication for stronger security. It also supports role-based access control to decide what each user can see or do, plus features like passwordless login, breached-password detection, and rules that customize the login flow.
Why it matters for your business
Authentication is easy to get wrong and expensive when you do, since a single flaw can expose every account. Offloading it to a proven provider like Auth0 speeds up development and reduces risk, which is why it often appears in backend development, full-stack, and SaaS development projects. A skilled team integrates Auth0 with your database, APIs, and app so sign-in is secure and seamless.
Where we use it
Related Zen in Tech services
How our team puts Auth0 to work in real projects.
FAQ
Auth0 — common questions
Is Auth0 worth it, or should we build our own auth?
For most teams, Auth0 is worth it. Building secure authentication in-house means handling password hashing, token management, MFA, and ongoing security patches correctly and forever. Auth0 provides that out of the box. Building your own usually makes sense only at very large scale or with unusual requirements.
How much does Auth0 cost?
Auth0 has a free tier for a limited number of monthly active users, then paid plans that scale with your user count and features like advanced MFA and enterprise SSO. Pricing is based mainly on monthly active users, so costs grow as your app does.
Auth0 vs Firebase Authentication or AWS Cognito?
All three are managed auth services. Auth0 is known for flexibility, strong enterprise SSO, and extensive integrations. Firebase Auth is simple and tied to Google's ecosystem, while Cognito fits teams already standardized on AWS. The right choice depends on your stack, budget, and enterprise needs.
Need Auth0 done right?
Book a free consultation and we’ll map the fastest, most cost-effective path for your project.
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