Supabase and Firebase are two of the most popular backend-as-a-service platforms to build and scale applications. Both are comprehensive products and provide realtime databases, file storage, authentication, client SDKs with good developer experience. However, there are some major differences -

Complex Queries:

Supabase uses PostgreSQL, an open-source object-relational database system that supports complex queries. Firebase offers two types of databases: Realtime Database (a NoSQL cloud database) and Cloud Firestore (an advanced NoSQL cloud database). They are optimised for performance at scale but don't support as complex querying as PostgreSQL.

Example SQL Query (Supabase/PostgreSQL)

Imagine you have two tables, orders and products, and you want to find the total amount spent on each product by each customer, along with product details, but only for those customers who have spent more than a certain amount on products in a specific category. Here's how you might write this query in SupaBase:


SELECT
    customers.name AS customer_name,
    products.name AS product_name,
    SUM(orders.quantity * products.price) AS total_spent
FROM
    orders
JOIN
    customers ON orders.customer_id = customers.id
JOIN
    products ON orders.product_id = products.id
WHERE
    products.category = 'Electronics'
GROUP BY
    customers.name, products.name
HAVING
    SUM(orders.quantity * products.price) > 500;

In Firebase, particularly in Firestore (Firebase's advanced database), queries are more limited:

No JOIN Operations: Firebase does not support traditional SQL-like JOIN operations. Instead, you would need to perform separate queries for each collection and then manually combine the data in your application code.
No Complex Aggregations: Firestore does not support complex aggregations like SUM, AVG, or HAVING clauses natively.

Functions (Serverless)

Firebase has Cloud Functions, which allow you to run backend code while Supabase does not have a native, integrated serverless function platform but can integrate with third-party services like AWS Lambda or Azure Functions.

Analytics

Supabase does not have a built-in analytics solution but can be integrated with third-party analytics tools. Firebase provides app analytics with detailed event reporting and user demographics like

User Engagement: Track how users engage with your app, including session length, app opens (active users), and frequency of use.
Demographics: Understand the demographic makeup of your users, such as age, gender, interests, and location.
Device Information: See what types of devices and operating systems your users are using, including device models, operating system versions, and screen sizes.
User Behavior: Track how users navigate through your app and which features they use. You can log custom events to track specific actions within your app, such as adding items to a cart, completing purchases, or achieving game levels.
Funnel Analysis: Analyze how users are completing a series of steps in your app (a funnel), such as the steps from adding an item to a cart to completing a purchase.

Pricing Model

Supabase provides tiered subscription models with limits going from Free, Pro (25$ / month) to Team (599$ / month) while Firebase charges basis number of reads, writes, storage etc

Reliability & Ecosystem:

Firebase offers a range of prebuilt extensions that integrate with other Firebase and Google Cloud services. It benefits from a large ecosystem due to its maturity and Google backing. Which means file storage is more scalable, client libraries are more comprehensive, has in-built app analytics and is far more battle tested. While Supabase doesn't have some of these in-built functionality but can be extended with PostgreSQL extensions, community plugins, and third-party services.

Conclusion

As always, the choice depends on your requirements

Choose Supabase when:

You Prefer SQL Databases: If you or your team are more comfortable with SQL databases or If your application requires complex data relationships or advanced database features, Supabase’s PostgreSQL backend offers more flexibility.
Open-Source Solutions are a Priority: If using open-source software is important for your project's philosophy, compliance, or cost considerations, Supabase, being an open-source alternative, would align well with your needs.
Self-Hosting is Required: If you need or prefer to host your backend infrastructure on your own servers or a private cloud for reasons such as data sovereignty, compliance, or cost, Supabase provides an option for self-hosting.

Choose Firebase when:

Rapid Development and Deployment: If your primary goal is to prototype and deploy quickly, Firebase offers a more comprehensive set of integrated services (like hosting, storage, real-time databases, and cloud functions) that can speed up development.
You Prefer NoSQL Databases: If your application’s data structure is more suited to a NoSQL database, or you prefer the scalability and flexibility that comes with NoSQL, Firebase’s Firestore and Realtime Database are robust options.
You Need Real-time Data Syncing: For applications that require real-time data updates, such as chat apps or live-updating dashboards, Firebase provides more mature and integrated real-time syncing capabilities.
You Want Seamless Integration with Google Services: If you are heavily invested in Google Cloud Platform or plan to leverage other Google services, Firebase integrates seamlessly with Google's ecosystem, providing an advantage in terms of connectivity and data movement.
You Require Advanced Analytics and Machine Learning Integration: Firebase offers powerful analytics solutions integrated with Google Analytics, and easy integration with machine learning services, which can be a deciding factor for data-driven applications.
Automatic Scaling is a Must: If you anticipate variable or growing traffic and want a backend that scales automatically without much configuration, Firebase provides a highly scalable infrastructure with minimal maintenance.

Firebase vs Supabase