Auth.js vs Stack Auth: Features, Pricing and User Reviews 2026
Compare features, pricing, reviews, and more to make an informed decision
Auth.js
Auth.js is a free, open-source authentication library for web applications, supporting OAuth, magic links, and credentials across multiple frameworks.
Stack Auth
Stack Auth is an open-source authentication platform that handles login, signup, and user management for developers in minutes.
Auth.js
Auth.js is a free, open-source authentication library for web applications, supporting OAuth, magic links, and credentials across multiple frameworks.
Stack Auth
Stack Auth is an open-source authentication platform that handles login, signup, and user management for developers in minutes.
Auth.js
OAuth 2.0 and OpenID Connect support
80+ pre-configured authentication providers
Magic link email authentication
Username and password credentials
WebAuthn passwordless login
Multiple framework support (Next.js, SvelteKit, Express)
Database adapters for major databases
JWT or database sessions
Built-in security features
Custom page support
TypeScript ready
Open source and free
Stack Auth
Password, OAuth, and magic link authentication
Two-factor authentication and passkeys
Team and organization management
Role-based permissions and access control
Pre-built React components and UI
User impersonation for support
Webhooks and real-time notifications
Custom email templates
REST API for integrations
Open-source and self-hostable
Next.js, React, JavaScript support
Admin dashboard for user management
Auth.js
Auth.js is completely free to use with no pricing tiers or hidden costs. As an open-source project, it is licensed under the ISC license, which allows anyone to use, modify, and distribute the software freely for both personal and commercial projects.
There are no subscription fees, no usage limits, and no charges for any features. All capabilities, including support for unlimited providers, database integrations, and advanced security features, are available at no cost. This makes Auth.js an excellent choice for projects of any size, from small personal websites to large enterprise applications.
The project is maintained by a community of contributors and is now part of Better Auth Inc. Developers can contribute to the project, report issues, and access community support through GitHub discussions completely free of charge.
Stack Auth
Stack Auth offers transparent pricing that scales with your needs. The Free plan is perfect for individuals and small projects, supporting up to 10,000 users with unlimited projects and teams. You get one dashboard administrator and access to all core authentication features.
The Team plan costs $49 per month and increases your user limit to 50,000 users. It includes three dashboard administrators, with additional admins available at $49 each. This plan is ideal for early startups and small teams building their products.
The Growth plan at $299 per month removes all user limits entirely. You get unlimited users, projects, and teams, along with five dashboard administrators included. Additional admins cost $49 each. This plan is designed for growing businesses that need to scale without worrying about user count restrictions.
All plans include the same core features, with the main differences being user limits and admin accounts.