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PowerSync vs WatermelonDB

PowerSync: Sync engine that keeps on-device SQLite in sync with Postgres, MongoDB, MySQL or SQL Server. WatermelonDB: Lazy-loading reactive database for React Native and React apps, built on SQLite.

key differences

  • Licensing: PowerSync is source-available (FSL-1.1-ALv2 (service); Apache-2.0 client SDKs); WatermelonDB is open source (permissive) (MIT License).
  • PowerSync is built for larger datasets (≤ 10 TB) than WatermelonDB (≤ 100 GB).
  • Horizontal scaling is native in PowerSync and none in WatermelonDB.
  • Transactions: PowerSync offers full ACID; WatermelonDB offers limited.
  • Only PowerSync has joins, json, encryption at rest, runs in webassembly.

choose powersync for

  • +Offline-first field-service and inspection apps
  • +Migrating off Realm/Atlas Device Sync
  • +Flutter and React Native apps on a Postgres or MongoDB backend
  • +Local-first web apps with SQLite in the browser

best at · Mobile/offline, Local-first, Embedded

choose watermelondb for

  • +Offline-capable React Native productivity apps
  • +Apps with large local lists that must render instantly
  • +Custom sync to an existing REST backend

best at · Mobile/offline, Local-first, Embedded

PowerSyncSync engine that keeps on-device SQLite in sync with Postgres, MongoDB, MySQL or SQL Server.
WatermelonDBLazy-loading reactive database for React Native and React apps, built on SQLite.
overview
Primary model
Relational
Relational
Also supports
–
–
Type
Database engine
Embedded library
Status
Active
Active
Developer
JourneyApps (Journey Mobile, Inc.)
Nozbe
First release
2023
2018
Latest version
service 1.27.2 (Oct 24, 2026)
0.28.0 (Apr 7, 2025)
License
Source-availableFSL-1.1-ALv2 (service); Apache-2.0 client SDKs
Open source (permissive)MIT License
Free tier
✓
✓
popularity
WhichDB Score
23.3
17.8
Rank
#129
#187
GitHub stars
395
11.8K
Stack Overflow questions
–
46
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Small (≤ 100 GB)
Horizontal scaling
Native
None
Multi-region
Read replicas
None
ACID
Full
Limited
Consistency
Causal, Eventual
Eventual
Schema
Strict
Strict
Architecture
Client server, Embedded
Embedded
deployment
Self-hosted
✓
✓
Vendor-managed cloud
✓
—
Serverless
—
—
Embedded
✓
✓
Edge
—
—
Clouds
–
–
capabilities
Transactions
✓
✓
Joins
✓
—
Secondary indexes
✓
✓
Full-text search
—
—
Vector search
—
—
Geospatial
—
—
JSON
✓
—
Change data capture
—
—
Triggers
—
—
Stored procedures
—
—
Materialized views
—
—
TTL / expiry
—
—
Pub/Sub
—
—
Columnar storage
—
—
In-memory
—
—
Durable persistence
✓
✓
Compression
—
—
Encryption at rest
✓
—
Role-based access
—
—
Time travel
—
—
Branching
—
—
Online schema changes
—
—
Streaming ingest
—
—
Offline sync
✓
✓
Runs in WebAssembly
✓
—
interfaces
Query languages
SQL (SQLite on device), Sync Rules / Sync Streams (SQL-like)
WatermelonDB Query API (Q)
Client languages
Dart, JavaScript, Kotlin, Swift, C#
JavaScript, TypeScript
Best for
Mobile/offline, Local-first, Embedded
Mobile/offline, Local-first, Embedded
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PowerSync vs WatermelonDB: FAQ

What is the difference between PowerSync and WatermelonDB?

PowerSync: Sync engine that keeps on-device SQLite in sync with Postgres, MongoDB, MySQL or SQL Server. WatermelonDB: Lazy-loading reactive database for React Native and React apps, built on SQLite. Licensing: PowerSync is source-available (FSL-1.1-ALv2 (service); Apache-2.0 client SDKs); WatermelonDB is open source (permissive) (MIT License). PowerSync is built for larger datasets (≤ 10 TB) than WatermelonDB (≤ 100 GB). Horizontal scaling is native in PowerSync and none in WatermelonDB.

When should I choose PowerSync over WatermelonDB?

Choose PowerSync for offline-first field-service and inspection apps; migrating off Realm/Atlas Device Sync; and flutter and React Native apps on a Postgres or MongoDB backend. Choose WatermelonDB for offline-capable React Native productivity apps, apps with large local lists that must render instantly and custom sync to an existing REST backend.

Is PowerSync or WatermelonDB more popular?

PowerSync ranks #129 on the WhichDB Score (23.3/100) and WatermelonDB ranks #187 (17.8/100). Popularity is not fit: check the requirements that matter for your project.

Are PowerSync and WatermelonDB open source?

Not in the OSI sense. PowerSync is source-available: you can read the code, but the license restricts some uses, typically offering it as a competing managed service. License: FSL-1.1-ALv2 (service); Apache-2.0 client SDKs. Yes. WatermelonDB is open source. License: MIT License.