Auth0 vs Supabase Auth for Solo Developers

Quick Comparison

Auth0 Overview

Auth0, owned by Okta, is the identity platform built for enterprise-scale authentication. It handles social logins, passwordless, MFA, SAML SSO, SCIM provisioning, machine-to-machine tokens, and fine-grained RBAC. The Universal Login page authenticates users on Auth0's domain, keeping credentials off your servers.

The platform is deeply configurable. Actions let you run serverless hooks during login flows. Organizations let you manage multi-tenant B2B structures. Compliance certifications (SOC 2, HIPAA) are available on higher tiers. Documentation is comprehensive across every framework and language.

I used Auth0 for a project where a corporate client required Okta SAML SSO. Configuring it took a few hours, but once running, the enterprise login flow worked flawlessly. When you need features like that, Auth0 earns its complexity.

Supabase Auth Overview

Supabase Auth is the authentication layer built into Supabase. It supports email/password, magic links, phone auth, and social OAuth providers (Google, GitHub, Apple, and more). Because it's part of the Supabase platform, auth integrates directly with your PostgreSQL database and Row Level Security policies.

The standout feature is how auth and database security work together. You write RLS policies that reference auth.uid(), and your database enforces access control at the query level. No middleware, no custom authorization code. The database itself knows who the user is and what they can access.

I use Supabase Auth in a project where the entire backend is Supabase. Users sign up, RLS policies kick in, and data is automatically scoped to the authenticated user. The integration eliminated an entire category of authorization bugs.

Key Differences

Free tier. Supabase Auth gives you 50,000 MAU for free. Auth0 gives you 7,500. For a solo developer building a consumer app, Supabase's free tier means auth costs nothing until you have significant traction. Auth0's limit arrives much sooner.

Database integration. Supabase Auth stores users in your own PostgreSQL database and integrates with Row Level Security. This is powerful because security logic lives at the database level, not in application code. Auth0 is a standalone identity service. It authenticates users but doesn't know anything about your database. You handle authorization in your app.

Enterprise features. Auth0 has SAML SSO, SCIM user provisioning, advanced MFA options, and compliance certifications. Supabase Auth has basic MFA and social logins but no enterprise SSO or SCIM. If you need to support enterprise customers who require SAML login, Auth0 is the only real option here.

Data ownership. With Supabase Auth, user data sits in your PostgreSQL database. You can query it, export it, and migrate it freely. With Auth0, user data lives on Auth0's servers. You can export via API, but you're dependent on their platform for access. If owning your auth data matters, Supabase wins.

Self-hosting. Supabase is open source and can be self-hosted. Auth0 is a closed SaaS platform. If you want to run auth on your own infrastructure eventually, Supabase gives you that option. Auth0 does not.

Configuration complexity. Auth0 has applications, connections, rules, actions, and organizations to configure. There's a learning curve before you're productive. Supabase Auth requires enabling providers in the dashboard and initializing the client. The simpler model gets you to authenticated users faster.

When to Choose Auth0

• You need SAML SSO for enterprise B2B customers
• Compliance certifications (SOC 2, HIPAA) are required
• You want auth decoupled from your database platform
• You need advanced auth flows (machine-to-machine, SCIM provisioning)
• You're building complex multi-tenant applications with deep org structures

When to Choose Supabase Auth

• You're using Supabase for your database and backend
• The 50,000 MAU free tier matters for your budget
• You want auth integrated with Row Level Security policies
• Data ownership and the option to self-host matter to you
• You're building a consumer app without enterprise SSO requirements

The Verdict

For most solo developers, Supabase Auth is the stronger pick. The 50,000 MAU free tier, database-level security integration, and simple setup make it the practical choice. If you're using Supabase as your backend already, choosing anything else for auth would mean giving up the RLS integration, which is one of Supabase's best features.

Auth0 is the right choice when your product serves enterprise customers. If buyers ask "do you support SAML SSO?" during sales calls, Auth0 answers that question. Supabase Auth isn't built for that use case and likely won't be anytime soon.

My recommendation: use Supabase Auth if you're in the Supabase ecosystem or building consumer products. Use Auth0 if enterprise SSO is a real requirement today, not a hypothetical future need. Don't pay for enterprise auth capabilities you won't use for years.