Permit.io is described as 'The permissions infrastructure for the internet. It fullstack authorization solution that enables developers to bake in access control into their code in minutes and be ready for future requirements from customers and regulators' and is an app. There are more than 10 alternatives to Permit.io for a variety of platforms, including Self-Hosted, SaaS, Web-based, Mac and Linux apps. The best Permit.io alternative is Keycloak, which is both free and Open Source. Other great apps like Permit.io are Better Auth, Amazon Cognito, Authorizer (authentication) and Logto.