Auth.js vs Auth0: Features, Pricing and User Reviews 2026

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.

Auth0 offers flexible pricing for different business needs with separate plans for consumer-facing applications and business software.

For B2C Applications (Business to Consumer), the Free plan supports up to 25,000 monthly active users with basic features. The Essentials plan costs $35 monthly for 500 users and includes multi-factor authentication and better limits. The Professional plan is $240 monthly for 1,000 users with advanced security features. Enterprise plans offer custom pricing with dedicated support and guaranteed uptime.

For B2B Applications (Business to Business), pricing starts higher. The Free plan includes the same 25,000 users. Essentials costs $150 monthly, Professional is $800 monthly, and Enterprise plans are available with custom pricing. All paid plans can be billed monthly or yearly, with yearly billing offering one month free.