Firebase and Supabase both promise to give teams a full‑featured backend without managing servers. Firebase, owned by Google, combines a NoSQL database with authentication, file storage and serverless functions. Supabase is an open‑source alternative built on Postgres that offers similar services—auth, storage, real‑time, and functions, but with the predictability of SQL and the freedom to self‑host. Choosing between them depends on how your application models data, how you plan to scale, and your tolerance for vendor lock‑in.
What is Supabase?
Supabase is an open‑source backend platform that runs on Postgres. Each project comes with a dedicated Postgres database, an auto‑generated REST and GraphQL API, real‑time subscriptions, and storage, all tied together with Row‑Level Security (RLS). RLS policies are written in SQL and allow you to define granular access rules using the same language you use for your data. Because Supabase’s core services are built on open technologies like Postgres and GoTrue, you can run Supabase locally or host it yourself using Docker or community tools such as Kubernetes or Terraform.
What is Firebase?
Firebase is a managed platform owned by Google. It includes Cloud Firestore (a document‑oriented NoSQL database), authentication, Cloud Storage for files and Cloud Functions for backend logic. Firestore stores data as JSON‑like documents grouped in collections. The SDKs automatically cache documents on the device so apps can read, write and listen to data while offline; changes are synchronized when the device reconnects. Firestore supports collection group queries, which let you query across collections with the same name. To handle relational data you often denormalize documents or perform multiple queries in code.
Core architecture and database
| Feature | Firebase | Supabase |
|---|---|---|
| Database type | Document database (Cloud Firestore) | Relational database (Postgres) |
| Data model | Schemaless JSON; subcollections; no native joins | Structured tables with foreign keys and indexes |
| Transactions | Supports transactions and batched writes | Full ACID transactions built into Postgres; you can execute complex joins, subqueries and data transformations in SQL |
| Offline support | Firestore caches actively used data on the client so you can read/write while offline; changes sync when connectivity returns | Supabase clients use Postgres directly; offline access requires your own caching strategy and works with Zero, Electric, |
| API access | Client SDKs for web, Android, iOS and server environments; REST/gRPC endpoints | Auto‑generated REST API via PostgREST and GraphQL API via pg_graphql |
| Self‑hosting | Not supported; services run on Google Cloud | Fully self‑hostable via Docker or on your own cloud |
Firestore’s schemaless design makes it easy to prototype. As data relationships grow more complex, you must handle joins in the client or denormalize your data. Supabase’s Postgres foundation gives you SQL’s expressive power, foreign keys, and indexes from day one.
Authentication and user management
| Feature | Firebase | Supabase |
|---|---|---|
| Login methods | Email/password, phone, anonymous and OAuth providers; additional SAML and OpenID Connect support requires upgrading to Firebase Authentication with Identity Platform | Email/password, OAuth providers (Google, GitHub, Apple, etc.), SMS and custom providers |
| Enterprise auth | The Identity Platform upgrade enables multi‑factor auth, SAML and OIDC | SSO, SAML and OIDC are available on Pro and Enterprise plans without changing SDKs |
| Access control | Security Rules use a domain‑specific language and differ for Firestore, Storage and Functions | Row‑Level Security (RLS) policies written in SQL control access across the database |
| Offline auth | The client SDK persists auth tokens locally and handles session renewal | Session management integrates with Postgres; tokens are validated on the server |
| Customization | Custom auth requires writing Cloud Functions or backend services | You can write custom policies and logic in SQL; column‑level security enables field‑level restrictions |
Firebase Authentication is easy to set up for email/password and social logins. Enterprise features such as SAML/OIDC and blocking functions require upgrading to the Identity Platform and come with new usage limits. Supabase Auth integrates with Postgres, so you can enforce complex policies using SQL and upgrade to SSO or enterprise auth features without changing products.
Serverless functions and backend logic
| Feature | Firebase | Supabase |
|---|---|---|
| Runtime | Cloud Functions run on Google’s infrastructure. You write code in JavaScript or TypeScript and deploy through the Firebase CLI; Python support is available in the second‑generation runtime | Edge Functions run on Deno and are globally distributed at the edge for low‑latency execution |
| Languages | JavaScript, TypeScript and Python (2nd gen) | TypeScript (via Deno); you can also call third‑party APIs or write SQL from functions |
| Triggers | HTTP requests, Firestore, auth events, Storage, pub/sub and scheduled jobs | HTTP requests, scheduled jobs and other triggers; functions can call Postgres directly through the supabase-js client |
| Cold start | Functions run in a managed environment; cold starts can vary depending on region and load | Edge Functions start quickly because Deno’s runtime is lightweight and runs close to users |
Firebase Cloud Functions integrate tightly with other Firebase products and support a wide range of triggers. Supabase Edge Functions are TypeScript functions that run on Deno at edge locations. They talk directly to your Postgres database, which simplifies tasks like handling webhooks or building custom APIs.
Storage and file management
| Feature | Firebase | Supabase |
|---|---|---|
| Underlying platform | Cloud Storage for Firebase (built on Google Cloud Storage) | S3‑compatible object store integrated with Postgres |
| Resumable uploads | The web SDK provides uploadBytesResumable()and methods to pause, resume or cancel an upload | Built‑in support for resumable uploads; each upload is recorded in a Postgres table |
| Access control | Security Rules use a separate rules language for Storage | Storage metadata is stored in Postgres and protected by the same RLS policies as the rest of your data |
| Image tools | No built‑in transformations (you can add Firebase Extensions for resizing) | Built‑in image transformations and CDN delivery |
| Free tier | Spark plan includes 5 GB of Cloud Storage in select regions; additional usage is billed by region and operation | Free plan allows files up to 50 MB and 1 GB total storage; Pro/Team plans allow up to 500 GB per file and include CDN |
Firebase Storage is reliable and integrates with the auth SDK. Pricing depends on region and includes separate charges for storage, bandwidth and operations. Supabase Storage integrates with Postgres: metadata is stored in a table, so you can apply the same RLS policies you use elsewhere. Free plans include 50 MB per file, and Pro plans raise that limit to hundreds of gigabytes.
Open source vs. proprietary
| Feature | Firebase | Supabase |
|---|---|---|
| Core platform | Proprietary managed services hosted by Google; client SDKs are open source. No self-hosting option. | Fully open source; core components such as Postgres, GoTrue and PostgREST are licensed under permissive licenses, and you can run Supabase yourself |
| Self‑hosting | Not available | Supported via CLI and Docker; community tools exist for Kubernetes, Terraform and other platforms |
| Governance | Maintained by Google | Community‑driven with a public roadmap and contribution model |
| Vendor lock‑in | Tight coupling to Google Cloud products | Portable architecture; you can move between Supabase Cloud and self‑hosted deployments without rewriting your app |
Firebase provides a polished, fully managed experience. Supabase embraces open source: you can inspect the code, contribute to improvements and, if needed, host your own Supabase instance.
Pricing and cost comparison
| Feature | Firebase | Supabase |
|---|---|---|
| Free tier | Spark plan includes a limited free quota—for example, Firestore allows 50,000 document reads and 20,000 writes per day, Storage includes 5 GB in select regions and Cloud Functions are limited | Supabase’s free plan includes unlimited API requests, 50,000 monthly active users, 500 MB database storage, 1 GB file storage and 5 GB bandwidth |
| Billing model | Pay‑as‑you‑go; you pay per document read, write, delete and per function invocation. Pricing varies by region and can be hard to predict | Transparent tiered pricing: pay for database storage, file storage, and compute. There are no charges for API requests, and you can track usage from the dashboard |
| Self‑hosting | Not supported | Available—self‑hosting lets you control costs and comply with regulatory requirements |
Firebase’s usage‑based pricing can surprise teams as their apps grow because every document read, write or listener contributes to cost. Supabase offers predictable tiers and does not bill per request, which can simplify budgeting.
Ecosystem, extensibility and community
| Feature | Firebase | Supabase |
|---|---|---|
| Platform integration | Deep integration with Google Cloud services such as BigQuery, Cloud Functions and Firebase ML | Built on Postgres; you can leverage Postgres extensions, listen to database events and integrate with third‑party services |
| Extensions | Firebase Extensions provide pre‑built functionality (e.g., image resizing, Stripe sync) | Postgres extensions (50+ preconfigured) add features like full‑text search, vector similarity and custom data types |
| SDKs | Official SDKs for web, Android, iOS, Unity, C++ and more | Official JavaScript client and community clients for Go, Rust, Dart and other languages |
| Community | Support via GitHub issues, Stack Overflow and Firebase Summit | Active open‑source community with GitHub discussions, the SupaSquad advocacy program and third‑party integrations |
| Self‑hosting tools | None | Community‑maintained packages for Terraform, Kubernetes and BYO cloud |
Firebase benefits from Google’s ecosystem and has mature SDKs for many platforms. Supabase leverages the Postgres ecosystem and open‑source contributions; you can extend it with Postgres extensions or third‑party packages.
Scalability and performance
Firestore scales automatically and handles real‑time synchronization for simple use cases. Queries are shallow and cannot traverse relationships; collection group queries allow searching across collections with the same name. Firestore caches data on the client so offline access is good. Deep querying often requires multiple reads or denormalized data, which can increase costs.
Supabase inherits Postgres’s mature scaling features. You can perform joins, subqueries and full‑text search in a single SQL statement. Transactions guarantee consistency, and indexes keep queries fast. Real‑time updates are delivered via Postgres logical replication, and connection pooling and read replicas can be added as your load grows. Because Supabase is built on a relational database, data remains strongly consistent, and performance tuning is well understood in the Postgres ecosystem.
Migrating from Firebase to Supabase
Many teams start with Firebase for fast prototyping and switch to Supabase when their data model becomes relational or costs become unpredictable. A typical migration involves two phases:
- Run both services side by side. Export your Firestore collections and import them into Supabase—initially as JSON or JSONB columns—while your app continues to read from Firebase. Then incrementally swap Firebase SDK calls for Supabase queries.
- Normalize your data. Refactor JSON into proper Postgres tables, add foreign keys and indexes and write RLS policies. This is when you begin to enjoy SQL’s power and simplified code.
Supabase provides open‑source migration tools. There is a utility for migrating Firebase Authentication to Supabase Auth by exporting users and re‑creating them in Postgres, another for copying Firestore collections to Postgres tables, and a tool for migrating files from Cloud Storage to Supabase Storage. These tools are maintained on GitHub and have been used by startups to migrate tens of thousands of users with minimal downtime.
Conclusion
Firebase offers an excellent developer experience for prototypes and simple applications. It excels at real‑time synchronization and has a generous free tier. Supabase provides a similar developer experience with a relational core. By building on Postgres and open‑source components, Supabase gives you SQL queries, ACID transactions, RLS and the option to self‑host. For teams that anticipate complex data relationships, need fine‑grained access control, or want predictable costs and open‑source flexibility, Supabase is a compelling alternative.
Need help migrating from Firebase to Supabase? Contact our Firebase Migration Team.