Firebase and Auth0 by Okta both offer robust authentication solutions, but they cater to different needs. Firebase is known for its ease of use, low price per monthly active user, and generous free tier of 50,000 MAUs. It also supports a wide range of authentication methods including email/password, phone auth, magic links, two-factor authentication, and various social identity providers. On the other hand, Auth0 by Okta is an all-in-one package with features like social login, bot detection, UI components, anonymous users, single-sign-on, and multi-factor authentication. However, its pricing is relatively expensive, with 20,000 MAUs costing $1400/month. If cost and ease of use are your primary concerns, Firebase might be the better option. If you need a more comprehensive set of features and are willing to pay a higher price, Auth0 by Okta is a strong choice.

Firebase offers a more generous free tier compared to Auth0 by Okta. Firebase's free tier includes 50,000 monthly active users (MAUs), while Auth0 by Okta's free tier comes with only 7,500 MAUs. This makes Firebase a more attractive option for developers who are looking to manage a larger number of users without incurring costs.

Firebase tends to be more cost-effective for scaling compared to Auth0 by Okta. Firebase starts at $0.0055 per monthly active user (MAU) and can go as low as $0.0025 per MAU as you scale to millions of users. In contrast, Auth0 by Okta charges $1400 per month for 20,000 MAUs, which can be quite expensive as your user base grows. Therefore, Firebase is generally the more economical choice for applications that expect to scale significantly.

Firebase is generally considered easier to use compared to Auth0 by Okta. Users have highlighted Firebase's ease of use and straightforward implementation, especially for developers who are already using other Firebase services. Firebase's integration with other Google services also adds to its ease of use. While Auth0 by Okta offers a comprehensive set of features, its complexity might be higher, making Firebase the more user-friendly option for many developers.

Firebase is Google's app development platform that offers a comprehensive suite of features, including storage, cloud functions, monitoring, and user authentication. It supports multiple authentication methods such as email and password, phone authentication, magic links, two-factor authentication, and social identity providers like Google, Facebook, Apple, Microsoft, Twitter, GitHub, and OAuth access tokens.

Pros of Firebase include its ease of use, low price per monthly active user, a generous free tier, and easy SMS authentication. Currently, there are no user-generated cons for Firebase.

The free tier for Firebase includes 50,000 monthly active users (MAUs). Beyond that, pricing starts at $0.0055 per MAU and can go as low as $0.0025 per MAU as you scale to millions of users.

Firebase supports multiple authentication methods, including email and password, phone authentication, magic links, two-factor authentication, and social identity providers such as Google, Google Play Games, Facebook, Apple, Microsoft, Twitter, GitHub, and OAuth access tokens.

Auth0 by Okta is a B2C identity management solution that offers an all-in-one package including social login, bot detection, UI components, anonymous users, single-sign-on (SSO), and multi-factor authentication (MFA). The free tier includes 7,500 monthly active users (MAUs), but higher usage can become expensive, with 20,000 MAUs costing $1400 per month.

The main features of Auth0 by Okta include passwordless authentication, social login, multi-factor authentication (MFA), breach detection, brute-force protection, and extensive documentation and community support.

Pros of Auth0 by Okta include its support for passwordless, social, and multi-factor authentication, extensive documentation and community support, and built-in breach detection and brute-force protection. Cons include restrictions on active users and features in the free tier, and the higher cost of advanced tiers.