Firebase is a Backend as a Service (BaaS) platform that helps you build, test, release, and monitor web and mobile apps for end-users. Firebase provides numerous features out of the box, such as:
Database. At its core, Firebase is a cloud storage solution that allows you to store and retrieve data related to your application and service. Firebase provides two different cloud-hosted database options: the Firebase Realtime Database (NoSQL), and Cloud Firestore, the newer database for mobile app development, providing a more intuitive data model and faster queries compared to the former.
Authentication. Firebase’s authentication service is a natural extension to its database offering, allowing you to securely store user information. You can quickly enable various auth mechanisms with multi-platform support.
Notifications. Another important feature and a key differentiator from other databases is Firebase’s ability to push realtime updates to subscribed clients following any updates to the database. This feature enables the Firebase Realtime Database and Cloud Firestore to be used for several realtime use cases such as chat, newsfeeds, and multiplayer games.
Offline support. With Firebase, devices can continue publishing data to the database store even when offline. Firebase’s SDKs store the messages locally and wait for the device to reconnect to the internet. As soon as that happens, they transparently publish that data to the cloud storage.
App analytics. Firebase comes with a nice dashboard for visualizing your app’s activity, so you can make critical business decisions based on this data.
Rest of the backend. The only feature falling under an app’s “backend” we haven't covered yet is the server-side business logic for the app. Given that Firebase is powered by Google, this naturally extends its functionality via integrations with Google Pub/Sub, Google Cloud Functions, and other pieces of its cloud infrastructure offering. You could spin up your own server and host it with Google or go serverless and make use of cloud functions to manage all the logic.
If you’re looking for an alternative BaaS solution to replace Firebase completely, here are the most popular options worth investigating:
Parse. Open-source backend that can be deployed to any infrastructure that can run Node.js.
Supabase. Open-source Firebase alternative providing all the backend features you need to build a product.
Kuzzle. Open-source backend to develop web, mobile, and IoT applications.
Back4App. Low-code open-source backend solution. Based on Parse.
However, switching to an entirely new platform isn’t always necessary. There are scenarios where you could be interested in replacing a specific Firebase service with an alternative, more specialized solution, rather than completely removing Firebase from your tech stack. For example, if you’re looking for a more robust replacement for Firebase’s authentication service, you could opt for something like Auth0 to secure your Firebase apps.
As previously mentioned, Firebase allows you to send messages in realtime to client devices, which is useful for use cases such as chat and live multiplayer games. Both the Firebase Realtime Database and Cloud Firestore push updates in realtime to connected devices every time data changes. In addition to the two databases, there’s Firebase Cloud Messaging (FCM), a cross-platform messaging solution that enables you to send notifications across platforms (iOS, Android, Unity).
However, we should bear in mind that Firebase is a generalist service rather than a specialized one, so there are some limitations to using Firebase components for realtime messaging to client devices:
Tight coupling. The idea of coupling a realtime messaging service and a core database for storage is a somewhat peculiar one because the two not only vary in semantics, but also in levels of scalability.
Scaling limits and complexity. An instance of the Firebase Realtime Database can only scale to 200.000 concurrent connections, which might not be enough for large-scale use cases (for example, streaming live score updates to sports fans during the World Cup final). To increase the number of concurrent connections your system can handle, you can shard your data across multiple database instances. It’s worth noting that sharding is a complex and extremely tedious process with the onus of handling things almost entirely on the developer.
Depending on the scale and exact requirements of your use case, it might be worth exploring specialized, best-in-breed solutions for realtime messaging and notifications that you can connect to your Firebase backend, as opposed to using Firebase native capabilities for realtime messaging to client devices.
We’ll now look at some Firebase alternatives for realtime messaging and notifications:
The Ably serverless WebSocket platform
Azure Notification Hubs
As one of the earliest managed services launched on AWS, SNS is a distributed publish/subscribe solution used for application-to-application (A2A) and application-to-person (A2P) communication.
SNS topics are used to enable communication: producers publish messages to topics, and consumers subscribe to these topics to receive messages. You can deliver messages to various types of subscribers, such as AWS SQS queues, AWS Lambda functions, and HTTP endpoints. You can also use SNS to send SMS messages, email, and push notifications to end-user devices.
Airship provides a platform primarily used for creating engaging mobile app experiences. It allows you to send in-app messages and push notifications via different channels:
App (iOS, Android, Amazon, Windows)
Web (web browsers)
(Silent) push notifications for iOS and Android
Beyond its core messaging and push notifications features, Airship provides functionality like A/B testing, message automation workflows, analytics dashboards, and the ability to stream customer-level data from the Airship platform to other systems such as CRMs, data warehouses, and tools like Amazon Kinesis.
Ably is a serverless WebSocket platform designed for last-mile pub/sub messaging. Ably makes it easy for developers to build realtime experiences like chat, live dashboards, asset tracking, and cross-platform push notifications for millions of users, without the hassle of managing and scaling infrastructure.
Key Ably features and capabilities
Ably is underpinned by a globally-distributed, autoscaling network consisting of 16 datacenters and 307 edge acceleration points of presence.
Client SDKs for every major programming language and development platform.
Pub/sub APIs with rich features, such as message delta compression, multi-protocol support (WebSockets, MQTT, Server-Sent Events), automatic reconnections with continuity, presence, and message history.
Push notifications for browsers and iOS & Android devices.
Guaranteed message ordering and delivery.
Global fault tolerance and a 99.999% uptime SLA.
< 65ms round-trip latency for 99th percentile.
Elastic scalability to handle millions of concurrent clients.
Here are some more resources for further reading:
Learn more about the Ably platform (features and system properties).
Explore customer stories and find out how organizations like HubSpot, Mentimeter, and Genius Sports benefit from trusting Aby with their realtime needs.
Sign up for a free account and see what Ably can do for you.
Azure Notification Hubs is a managed service that allows you to send push notifications from on-prem and cloud backends to mobile devices across different platforms: iOS, Android, Windows, Baidu.
Azure Notification Hubs provide various delivery patterns for push notifications, such as:
Broadcast to one or more platforms.
Push to individual devices.
Push to a segment of users.
Scheduled push (notifications to be sent at your time of choice).
OneSignal is a solution for sending push notifications, in-app messages, SMS, and emails. It provides native SDKs for Android, iOS and Web Push, and cross-platform SDKs targeting frameworks such as Flutter, Xamarin, React Native, and Unity.
OneSignal provides features like:
Journeys. Workflow builder to automate messaging and build dynamic message flows.
Personalization. Helps you automate and send personalized messages based on realtime user behavior and preferences.
Segmentation. You can create targeted messaging campaigns based on realtime user engagement.
A/B testing. Multivariate testing capabilities so you can experiment with multiple messaging options and optimize performance.
We hope you’ve found this article useful as a starting point for discovering alternatives to Firebase functionality. We encourage you to conduct an in-depth analysis and evaluation to see which one of the solutions we’ve covered is the best choice for your specific use case.
If you’re looking for an easy way to reliably send realtime messages from your Firebase backend to millions of client devices, give Ably a go.
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