Comparing ZITADEL to Firebase

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ZITADEL is an open source identity platform that addresses the challenges of self-service, authentication, and authorization by integrating them into your project. It supports multi-tenancy for business-to-business (B2B), identity brokering, multifactor/passwordless authentication, delegated access management, in-context audit trail, OpenID Connect, SAML 2.0, and OAuth 2.0.

In contrast, Firebase is a backend as a service (BaaS) that provides developers with a variety of tools and services to help them build quality applications. It's categorized as a NoSQL database platform because the data is stored in a JSON-like format.

With ZITADEL, you can avoid hours of creating, configuring, and operating complex authentication and authorization systems. Meanwhile, Firebase on the other end provides you with commodity features for all of your backend needs, including cloud messaging, testing, crashlytics, authentication, and real-time databases.

Developing with a powerful and feature-rich platform can be essential in creating a reliable and high-quality mobile and web application. It takes a lot of dedication and time to manage files and resources, server configuration, analytics, and other related operations.

In this article, you'll compare ZITADEL and Firebase authentication and look specifically at where they differ in regard to their authentication and authorization features, integrations, and architecture.

ZITADEL vs. Firebase

ZITADEL and Firebase can both be used to achieve authentication and authorization in your application. However, there are a few factors, like authentication features and integrations, that can help you decide which platform is best for you. Let's take a look at the authentication features each platform offers:

Firebase Authentication

The main goal of an authentication provider is to be able to identify each user in your application, which is where Firebase Auth comes into play. With Firebase, you have to obtain an authentication credential from the user in order to sign them into your application. The user's email address and password or an OAuth token from a third-party service can serve as these credentials. If you choose to upgrade to Firebase Authentication with Identity Platform, you can authenticate users on your platform with any identity provider that supports OIDC or SAML.

You can incorporate a quick sign-up and sign-in feature for your users using FirebaseUI Auth. By doing so, users spend less time creating profiles or signing up, which boosts conversion rates. Additionally, it tackles scenarios that can be tricky to manage appropriately in terms of security, such as account recovery and account linkage. Furthermore, the Firebase SDK Authentication is also an authentication function you can include in your application. It gives you various authentication functions, including the following:

  • Email and password authentication: Users that sign in with their email addresses and passwords can be created and managed using the Firebase Authentication SDK.
  • Third-party-powered authentication: Google, Facebook, Twitter, and GitHub user accounts can be used to log in using the Firebase Authentication SDK's APIs.
  • Phone number authentication: Users can be authenticated after receiving a one-time password (OTP) SMS message on their phones.
  • Other authentication channels include custom authentication using a limited list of federated identity providers, any third-party identity providers on a pricier plan, and anonymous authentication for temporary accounts.

Firebase authentication can also be achieved using an identity platform. You have the option to add an optional authentication feature (like multifactor authentication, blocking function, multi-tenancy, SAML, and OIDC) to your application using the Identity Platform.

ZITADEL Authentication

ZITADEL provides you with the option to use third-party-powered authentication to provide trust between your application and the users. For instance, if you set Google as an identity provider, ZITADEL can redirect the user to log in with their Google account and give ZITADEL access to take their credentials as a form of identification on the platform.

You can use the following authentication features with ZITADEL:

  • You can register an OIDC client of your choice and add a ZITADEL callback redirect (make sure the provider is OIDC 1.0 compliant with a proper discovery endpoint. This will give your users the option to log into your ZITADEL-powered application using the OIDC authentication feature.
  • You can use a SAML sign-in option that gives your users the ability to authenticate once and gain access to multiple secured parts of your application without resubmitting their credentials.
  • You can choose to let your users log in with a traditional username and password.
  • You can authenticate via external identities, such as Google, Microsoft, or Apple.
  • You can force a user to register and use multifactor authentication through a universal second factor, such as OTP, alongside their pin.
  • You can decide to use passwordless login authentication. Your user can either use device-dependent (e.g., fingerprint, face recognition, and Windows Hello) or device-independent (e.g., YubiKey and SoloKeys) access.
  • You can use multi-tenancy authentication to allow a user to authenticate themselves once with authorizations in multiple organizations. It simplifies the whole authentication process for users regardless of their tenancy, while allowing you to have multiple organizations with different users. ZITADEL ensures each tenant has complete privacy regarding their data, a highly-customizable login flow, and on-demand scaling.

As you can see, both ZITADEL and Firebase provide numerous ways to authenticate your users. However, ZITADEL stands out in that it gives you open access to any third-party identity broker without any complex pricing plans. You can use OIDC or SAML to connect with any third-party identity provider and provide your users with the authentication they want.

If you're in need of a quick authentication feature for your application, Firebase is a good option. However, if you need more advanced authorization, user self-service, and multi-tenancy features for your application, ZITADEL is the superior choice because it's built to handle your authentication needs, no matter the complexity of your application.

Firebase Integrations

Programming in C++, Java, JavaScript, JavaScript/Node.js, Objective-C, and Swift is supported by the Firebase SDK. Database bindings and libraries with limited functionality in Angular, Backbone.js and Ember.js are also supported.

For the uninitiated, bindings are basic mappings of APIs to in-code functions that carry out standard operations like CRUD. However, they're not as detailed as SDKs, and sometimes a binding scan can go beyond the basic CRUD operations and offer cosmetic improvements or alternatives to existing methods and features, in which case they are often referred to as auxiliary or supplementary bindings.

Google has added a few supplementary bindings and libraries like FirebaseUI, GeoFire, Firebase Queue, and FirebaseJobDispatcher. These auxiliary bindings add more functionality to your application, including drop-in authentication with FirebaseUI and real-time location queries with GeoFire.

Additionally, Firebase allows for integration with Elasticsearch and the import of big JSON data collections. You can find out more about implementation in the official Firebase docs.

ZITADEL Integrations

ZITADEL is younger than Firebase and provides gRPC, gRPC-web, and Rest APIs, which are supported by most common programming languages, including Angular, React, Flutter, Next.js, Java, Python, Go, .NET, and Dart. In addition, you can opt for either the cloud SaaS version or self-host it using the open-sourced repo. To see a few different ways integrations can be used, check out ZITADEL's official docs.

ZITADEL provides ample APIs and SDKs to help you integrate with most programming languages. You can also easily integrate your apps with open standards such as OpenID Connect, OAuth 2.0, SAML, etc., when using ZITADEL.

Both ZITADEL and Firebase integrate with a wide range of programming languages, which gives you the ability to work with whatever language or framework you're most comfortable with.

Firebase Use Cases

As previously stated, Firebase is a full-featured BaaS platform, offering all the capabilities required to swiftly create complex, collaborative apps that can support millions of users. The architecture of Firebase is designed to work in any of the following situations:

  • Firebase-powered application: Firebase sits in between your application and your client. All you need to worry about is the client side of the application, while Firebase handles the complex backend structure. Resource sharing and storage are both handled by Firebase.
  • Firebase-powered application with server-side: Firebase is positioned between the server and clients in this architecture. In other words, your server interacts with Firebase to send and receive resources from clients. You can decide who has full access to the data and how it should be handled using your security settings and Firebase rules. Then your server code keeps an eye out for any data changes made by clients and reacts as needed. Even though you're still running a server, Firebase is handling all the heavy lifting of scale and real-time updates.
  • Firebase-powered functionality in an existing application: In this architecture, Firebase can be integrated alongside your existing server. Your clients will establish connections to both your server and Firebase, using Firebase to power your real-time features while keeping the rest of your application running smoothly.

Using any of these capabilities, you can add a real-time notification system for your users, integrate a chat feature into your website, produce a real-time comment feed, and more. An easy way to start using Firebase is to test out some of its minor functionalities.


ZITADEL offers you much more control over how your IAM system is deployed. You can use ZITADEL in any of the following use-cases:

  • Out-of-the-box integration with your apps: ZITADEL can offer you a central login experience that can handle all your users in one place. When a user requests to authenticate, you send them over to the central login widget of ZITADEL to retrieve their details once they're successfully authenticated.
  • Multi-tenancy support: When building business-to-business (B2B) apps, you need to enable your customers to have control over their authentication flow. They should be able to choose and customize things like branding, federation, and policies. This is often not possible with providers like Firebase Auth because it was originally intended for business-to-consumer (B2C) apps. ZITADEL enables you to support your B2B customers and provide their users with the best experience possible.
  • Self-service experience: As mentioned above, B2B customers need control over their branding and access rules, and it's not scalable for you to approve or moderate changes. ZITADEL offers you a complete self-service platform that your customers can use to easily self-manage their projects in your apps.
  • Using existing identities: Many B2B customers want to rely on established third-party identity providers or their own company logins instead of going down the generic email-password route. Federated login flows only partly solve this problem because they don't allow you to choose any third-party provider, and reusing a company login is an even more complex task. ZITADEL works best in this case since you can allow your customers to use common protocols like OIDC and SAML to register any recognized identity provider with the IAM solution and manage it on a centralized platform.

Internally, ZITADEL is composed of two principal architectural styles: command and query responsibility segregation (CQRS), and event sourcing (ES). Combining ES and CQRS improves ZITADEL's consistency and offers numerous advantages.

Due to the nature of Event Sourcing, ZITADEL has the singular ability to create a robust audit record of everything that occurs on its resources—all while maintaining storage costs and audit trail length.

In summary, if your application needs backend functionality, authentication needs, or real-time data alongside your existing server, Firebase gives you the ability to integrate it with your application at any stage (development or production). Meanwhile, ZITADEL's easy integration into your application helps you handle the authentication, authorization, and self-service parts of your application. If you're looking for a platform that will manage your user identity and provide you complete control over it, ZITADEL is the superior choice.


In this article, you learned about the key differences between Firebase Authentication and ZITADEL. You saw how they compared to each other and how you can integrate them into your project, their architectural choices, as well as the different features they offer.

Firebase in general provides you with backend functions that you can use while building your application's frontend or when scaling your applications. In contrast, ZITADEL gives you flexibility with your programming language and unlimited authentication options.

ZITADEL is an open source identity management platform that provides you with a wide range of features like OpenID Connect, SAML 2.0, OAuth 2, FIDO2, OTP, and an unlimited audit trail. With ZITADEL, you can solve all your authentication and authorization needs. Check out the ZITADEL repo and give us a GitHub star. We appreciate the feedback.

This article was contributed by Aransiola Ayodele.

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