Firebase is not one product; it is five products sold as a bundle: authentication, a NoSQL document database called Firestore, static hosting, serverless functions, and file storage, all wired together through one SDK and one dashboard. Searching for a firebase equivalent usually means one of two very different things: a single platform that bundles the same five pieces the same way, or a set of separate, well-chosen tools that each do one piece properly. The first option mostly means Supabase or Appwrite, both genuine, capable products. The second option, a managed Postgres database next to a small backend service, covers most of what people actually reach for Firebase to do, without the lock-in of a second bundled platform.
This post breaks Firebase into its five pieces and names the realistic swap for each one, whether that swap is a bundled competitor or a couple of plain, well-understood tools. None of it is a pitch for one single replacement, because that is exactly the trap Firebase itself sets: pick the bundle and stop comparing the parts. Read the piece you actually need replaced.
Table of contents
- What’s actually inside the Firebase bundle
- Authentication: the piece with the most direct equivalents
- Firestore: the document database, and why Postgres usually ends up covering it
- Hosting and functions: split into a static site and a backend service
- Storage: files still need somewhere to live
- Putting it back together: one database, one service
- How this fits the rest of the stack
- FAQ
What’s actually inside the Firebase bundle
Before comparing equivalents it helps to separate what Firebase actually sells, because most of the confusion in a search for a firebase equivalent comes from treating it as one thing. Firebase is a wrapper around five separate categories of infrastructure, each with its own market of standalone tools:
- Authentication. Email/password, magic links, and social sign-in, with session tokens issued and verified for you.
- Firestore. A NoSQL document database with realtime listeners, so a client can subscribe to a query and get pushed updates.
- Hosting. Static file hosting with a CDN in front, for the client-side app itself.
- Functions. Serverless functions that run backend logic without managing a server process.
- Storage. Object storage for user-uploaded files, tied into the same auth rules as the database.
A true one-to-one equivalent has to replace all five with the same wiring between them, which is why bundled Backend-as-a-Service products, Supabase and Appwrite being the two most cited, exist as a category of their own. The alternative, and the more common outcome once a team needs to scale or debug one of these pieces, is picking a standalone tool for each.
Authentication: the piece with the most direct equivalents
Authentication is the easiest piece to replace without missing anything, because the problem it solves, issuing and verifying a session token, is decades old and well understood outside of Firebase’s SDK. A backend service written in Node or any other language can implement it directly with a password-hashing library and signed JWTs, the DIY end of the spectrum. Self-hosted identity servers like Keycloak or Ory, and managed identity products from several vendors, sit in the middle: more setup than Firebase Auth, but no vendor lock-in on the token format or user records.
What is lost moving away from Firebase Auth is the drop-in client SDK that handles token refresh and social provider redirects. What is gained is that the user table is a normal table in a normal database, queryable with normal SQL, instead of a record that only really exists inside Firebase’s own console.
Firestore: the document database, and why Postgres usually ends up covering it
Firestore’s realtime listeners are the single hardest feature to replace exactly, and most equivalents do not try. What Firestore is underneath that feature is a document database: collections of JSON-shaped records with flexible schema. Relational databases used to be the wrong tool for that shape of data, before JSON and JSONB column types matured. A modern Postgres instance stores a JSON document in a column, indexes into it, and queries it about as flexibly as Firestore does, while also giving you joins, transactions, and constraints a pure document store does not.
The realtime piece is the genuine gap. Firestore pushes changes to subscribed clients automatically; a Postgres-backed service has to build that itself, typically with a small layer of webhooks or a subscription channel on top of the database. For an app that genuinely needs live-updating lists across many clients, that is real work. For the far more common case, an app that reads and writes data on request, a managed Postgres instance with ordinary request-response routes replaces Firestore without the client ever noticing the difference.
Hosting and functions: split into a static site and a backend service
Firebase Hosting and Cloud Functions are two separate products doing one combined job: serve the frontend, and run backend logic somewhere adjacent to it. That split maps directly onto ordinary web infrastructure. The frontend, whatever framework built it, deploys as a static site from a repository with a CDN and custom domain in front, the same way Firebase Hosting works. The backend logic that used to live in a Cloud Function becomes routes on a small backend service, in whichever language the team already knows, rather than a directory of individually deployed functions with their own cold-start behaviour.
The trade is explicit: Cloud Functions bill per invocation and scale to zero automatically, while a backend service is a running process with its own plan. For a function that fires rarely, that is a real cost difference. For anything called on most requests, a persistent service with normal logs and a normal deploy history is usually easier to reason about than a directory of individually versioned functions.
Storage: files still need somewhere to live
Firebase Storage is object storage with the same auth rules as the rest of the bundle applied to file access. The direct equivalent is persistent storage attached to whichever backend service handles uploads: the service authenticates the request using the same session logic as everything else, then reads or writes to storage attached to it, instead of a separate bucket with its own rule syntax to maintain.
The practical difference shows up in debugging. A storage rule written in Firebase’s own rules language is a small program that is hard to test outside of Firebase’s own emulator. A storage path checked inside a normal backend route is ordinary code, in the same language and the same debugger as the rest of the service.
Putting it back together: one database, one service
Lay the five pieces back out and the pattern is a managed Postgres database holding both the relational data and the JSON-shaped records that used to live in Firestore, next to a Node or Python backend service that owns authentication, the routes a frontend calls, and the storage paths for uploads. That is two things to run and connect, not one bundled console, and it is the shape covered in more detail in how a Postgres-backed backend actually gets built and in our direct Firebase versus Supabase comparison for teams deciding whether to stay inside a bundle at all.
It is also worth being clear about what this is not: it is not a Firebase clone, and nobody should go looking for one-to-one rule-file compatibility. It is the same five jobs done with a managed Postgres instance and a backend service you control, with deploy history and logs, the kind of view a dashboard should show regardless of which platform runs it.
How this fits the rest of the stack
The honest reason to leave a bundled backend is rarely the bundle itself; it’s the moment a query, a bill, or a rule file stops making sense and there’s no normal database underneath to inspect. A managed Postgres instance and a backend service replace most of what Firebase does, priced as two plain lines instead of one combined bill, and the RunxBuild hosting calculator shows both next to each other. Our comparison of Vercel and Firebase covers the hosting half of the same decision if the frontend is the piece still undecided.
Useful related references:
- Vercel vs Firebase: Frontend Delivery Against a Backend Toolkit
- Firebase vs Supabase: Document Store or Postgres, and What That Costs You Later
- Deleting a Firebase Auth Account Properly: The Data Nobody Remembers
- Services on RunxBuild
FAQ
Is there a direct one-to-one Firebase equivalent?
The closest bundled equivalents are Supabase and Appwrite, which package a Postgres or document database, authentication, storage, and functions the way Firebase does. Outside of a bundle, a managed Postgres database next to a backend service covers the same five jobs with different, more standard tooling.
Can Postgres actually replace Firestore?
For most apps, yes. Postgres’s JSONB column type stores and indexes JSON-shaped documents about as flexibly as Firestore does, while also giving you joins and transactions Firestore does not have. The genuine gap is Firestore’s realtime listeners, which a Postgres-backed service has to build separately rather than getting for free.
What is the open source equivalent of Firebase Authentication?
Self-hosted identity servers like Keycloak or Ory replace Firebase Auth’s server side, or a backend service can implement password hashing and JWT sessions directly. Either way, the resulting user records live in a normal, queryable table instead of only inside a vendor’s own console.
Does RunxBuild offer a Firebase alternative?
Not as a single bundled backend-as-a-service product. RunxBuild hosts the pieces that replace most of what Firebase does individually: managed Postgres and MySQL databases, and backend services for the auth, routing, and storage logic that used to live in Firebase’s SDK.
Why not just use Supabase instead of building the equivalent myself?
Supabase is a legitimate bundled option and the most direct like-for-like swap for Firebase. The tradeoff moving away from any bundle, Supabase included, is the same one moving away from Firebase: less setup up front, more platform lock-in later. Building it from a plain database and service avoids that second bundle entirely.