Auth0 vs Firebase

Auth0 and Firebase are competing application development platforms. Auth0 is an IAM solution enabling developers to add MFA, SSO, and passwordless login to their apps. Acquired in March 2021, Auth0 is now an Okta product. Firebase, from Google, is a mobile app oriented suite supporting customer authentication using passwords, phone, or social (federated) login. As competing solutions for adding customer login and authentication to apps, Firebase and Auth0 both tend to be deployed by cost conscious smaller companies that offer mobile applications to end users outside an organization.

Features

Depending on the developer’s intended use for an application, there are reasons to use either Firebase or Auth0.

For a simple customer authentication solution, Firebase Authentication presents a compelling solution. It supports authentication with a phone number, password, and federated identity providers like Google. When developers are building an app with a Firebase backend, it’s hard to beat a free, integrated solution with a low price that scales predictably with growth. Users of Firebase state that authentication is one of Firebase’s strongest components, and describe it as one of the very easiest solutions to implement long as developers don’t need more advanced user or identity management capabilities.

For apps facing greater security regulations or risk, or for apps with internal users, then Auth0 may present a better choice. Auth0 can provide a range of features that Firebases’s Authentication component does not offer. These features include a highly customizable authentication flow, integration with Active Directory or other enterprise identity management systems, social login where Google, Twitter, or Facebook are not a preferred option, more stringent or regulation compliant user data storage (e.g. HIPAA or GDPR compliance), and more powerful security features, like bot detection, and brute-force protection.

Limitations

While solid options, there are drawbacks to both Firebase’s Authentication solution for a mobile app, or Auth0’s.

Firebase Authentication presents a very simple solution. It is not sophisticated enough for advanced enterprise security needs or for stringent data compliance. For instance, if a project requires multi-factor authentication, breached password security, enterprise AD integration, integration with a backend database other than Firebase’s own (Firestore), or app user data enrichment, then another solution is preferred.

Auth0 can help developers with these issues, but users of Firebase for app development tend to be cost conscious. One of the foremost complaints against Auth0 is that while there are many functions available free, making it attractive to developers in the early stages of a product, pricing scales steeply, and it is frustratingly unclear at times what a needed or attractive feature may ultimately cost. 

Pricing

Auth0 is free with up to 7,000 external active users with unlimited logins. The developer plan, starting at $23 per month, supports 50,000 external MAUs and features unlimited social connections, and role management. The Developer Pro plan starts at $130 per month and supports up to 7,000 MAUs but adds 3 enterprise connections, pro MFA and enhanced password protection. For internal users, developers require the Developer Pro plan, starting at $220 per month for up to 500 employees (100 MAUs), or an Enterprise plan to support more than 500 employees or MAUs.

Firebase Authentication is free on a Firebase Spark plan, for up to 10k successful verifications  of app users each month. This service also includes Firebase services such as Crashlytics, A/B testing, and other mobile app analytics. For more than 10k successful user verifications, users move up to the Firebase Blaze plan. On the Blaze plan, authentications are $.01 per authentications from user verifications from the US, India, or Canada. Outside these regions, verifications are 6c per successful verification.

Auth0 is an identity management platform providing authentication and authorization as a service for app builders, and Firebase is an application development suite that includes components to support both web and mobile development. Developers building with Firebase apps may use Firebase’s own Authentication solutions (including the recommended FirebaseUI Auth component) to build a complete authentication solution for their mobile app, or they may integrate a preferred solution, such as Auth0. So While Auth0 can be integrated into a Firebase project, Firebase also competes with Auth0 by offering its own customer authentication solution for web and mobile apps built with Firebase. Firebase and Auth0 both tend to be deployed by cost conscious smaller companies, or small teams just getting off the ground.

Features

If building with Firebase, there are reasons to stick with Firebase’s own authentication app, vs adding Auth0, and vice-versa.

For limited login options and authentication where a Firebase database backend is being used for an application, Firebase Authentication is probably wholly adequate. It supports authentication with a phone number, password, or federated identity providers like Google. In this case, it’s hard to beat a free, integrated solution. Additionally, users of Firebase state that authentication is one of Firebase’s strongest components, and describe it as one of the very easiest solutions to implement around,so long as developers don’t need more advanced user or identity management capabilities.

If an app is not using Firebase’s database backend, then Auth0 instantly presents a more appealing option. Features that Auth0 can provide that Firebases’s Authentication component cannot include a highly customizable authentication flow, integration with Active Directory or other enterprise identity management systems, social login where Google, Twitter, or Facebook are not a preferred option, more stringent or regulation compliant user data storage (e.g. HIPAA or GDPR compliance), and more powerful security features.

Limitations

While solid options, there are reasons to not implement either Firebase’s Authentication solution for a mobile app, or Auth0’s.

As stated, Firebase Authentication specializes as a very simple solution. For advanced enterprise security needs or for stringent data compliance, it simply won’t do. For instance, if a project requires multi-factor authentication, breached password security, enterprise AD integration, integration with a backend database other than Firebase’s own (Firestore), or app user data enrichment, then another solution is a must.

Auth0 can help developers with these issues, but users of Firebase for app development tend to be cost conscious. One of the foremost complaints against Auth0 is that while there are many functions available free, making it attractive to developers in the early stages of a product, pricing scales aggressively, and sometimes surprisingly.

Pricing

Auth0 is free with up to 7,000 external active users with unlimited logins, or 500 insider active users. The paid developer plan adds additional features including up to 2 days of log retention and 1 log stream, role management, and other features, starting at $23 per month per 1000 external authenticated users, with additional tiers for more users; all tiers cost about $.23 per user. For employee support with social login, MFA, and enterprise identity support (e.g. Active Directory), the Developer Pro plan is required. Its pricing depends on the number of internal users, external users, and machine to machine tokens included.

Firebase Authentication is free on a Firebase Spark plan, for up to 10k successful verifications  of app users each month. This service also includes Firebase services such as Crashlytics, A/B testing, and other mobile app analytics. For more than 10k successful user verifications, users move up to the Firebase Blaze plan. On the Blaze plan, authentications are $.01 per authentications from user verifications from the US, India, or Canada. Outside these regions, verifications are 6c per successful verification.