best managed databases for real-time applications

When a user sends a chat message, moves a cursor on a collaborative whiteboard, or watches a dashboard update with fresh metrics — every millisecond matters. The database behind that experience isn't just storing data; it's pushing changes to clients in real time.

Not all managed databases handle this well. Some are built for real-time from the ground up. Others bolt it on as an afterthought. Here's what we recommend.

the picks at a glance

1. firebase (realtime database + firestore)

Best for: teams that want to ship a real-time app fast without managing servers.

Firebase offers two real-time databases. The original Realtime Database is a single JSON tree that syncs instantly across all connected clients — great for low-latency chat and presence indicators. Firestore is the newer, more structured option with richer queries, automatic scaling, and multi-region replication.1

Both use persistent WebSocket connections under the hood. When data changes on the server, Firebase pushes the delta to every subscribed client. No polling, no manual refresh.

The trade-off: you're locked into Google Cloud's ecosystem, and complex queries can get expensive at scale. Firestore's pricing is based on document reads/writes, which adds up fast for high-frequency real-time updates.

→ see firebase on the official site

2. supabase

Best for: developers who want an open-source Firebase alternative with real PostgreSQL under the hood.

Supabase wraps PostgreSQL with a real-time engine that listens to database changes and broadcasts them over WebSockets. It uses PostgreSQL's built-in LISTEN/NOTIFY mechanism plus a replication slot to capture INSERT, UPDATE, and DELETE events.2

Because it's PostgreSQL, you get proper SQL, joins, foreign keys, and all the relational goodness that Firebase lacks. The real-time layer is a separate server (Realtime) that sits alongside PostgREST and GoTrue — all open source.

The trade-off: you're running PostgreSQL, which means you need to think about connection pooling, indexing, and query performance yourself. Supabase handles the infrastructure, but the database internals are yours to tune.

→ see supabase on the official site

3. mongodb atlas

Best for: apps with flexible document schemas that need Change Streams for event-driven architectures.

MongoDB Atlas Change Streams let you subscribe to real-time data changes at the collection, database, or entire deployment level. Every write, update, or delete generates a change event that your application can consume and react to.3

Change Streams are resumable — if your client disconnects, it can pick up from the last known resume token. This makes them reliable for mission-critical event pipelines, audit logs, and cross-service synchronization.

The trade-off: Change Streams are oplog-based, which means they carry some overhead on write-heavy workloads. And MongoDB's document model, while flexible, means you give up the relational guarantees that Supabase (PostgreSQL) provides.

→ see mongodb atlas on the official site

4. pocketbase

Best for: small projects, MVPs, and embedded apps that need real-time without complexity.

PocketBase is a single Go binary that bundles an embedded SQLite database, a real-time subscription engine, file storage, and an admin UI. It supports real-time subscriptions over Server-Sent Events (SSE) and WebSockets, letting clients listen to record changes in any collection.4

The beauty of PocketBase is its simplicity. One binary, zero dependencies, and you get authentication, file uploads, and real-time sync out of the box. It's perfect for prototyping or shipping a small internal tool.

The trade-off: SQLite doesn't scale horizontally. For apps that need concurrent writes from thousands of users, you'll outgrow PocketBase quickly. It's a starting point, not an enterprise solution.

→ see pocketbase on the official site

comparison: nosql vs sql foundations

when to choose a managed baas vs. a managed database

The biggest decision isn't which tool — it's which category.

Managed BaaS (Firebase, Supabase) give you a database plus authentication, storage, serverless functions, and real-time sync as a single product. You write less glue code. The trade-off is less control over the database layer and, in Firebase's case, a proprietary query language.

Managed databases (MongoDB Atlas) give you a pure database with real-time capabilities bolted on via Change Streams or triggers. You own the application layer entirely. This is the right choice when you need full control over your data model, indexing strategy, and scaling behavior.

PocketBase sits in a third category — a self-contained BaaS that's closer to a framework than a platform. It's the best choice when you want BaaS convenience without cloud lock-in, and your scale requirements are modest.

our recommendation

• Building a chat app or collaborative tool today? Start with Firebase or Supabase. They handle the real-time plumbing so you don't have to.
• Need relational integrity and open-source? Supabase is the clear winner.
• Working with event-driven microservices or flexible documents? MongoDB Atlas Change Streams are battle-tested at scale.
• Just prototyping or building a small internal tool? PocketBase will get you to a working real-time app in minutes.

Disclosure: AskBuy earns affiliate commissions when you purchase through the links above. This doesn't affect our recommendations — we only recommend tools we've evaluated and would use ourselves.