Electric vs PowerSync
A comparison of Electric and PowerSync, the two leading local-first sync engines in 2026, covering their sync models, backend database support, conflict handling, write paths, and how far each is from production.
Quick Answer
Both sync a server database into local SQLite so apps work offline and update in real time. PowerSync is the more managed, production-proven option with multi-database support and declarative Sync Streams. Electric rebuilt its engine around a read-path sync model and is lighter-weight, with writes handled by your own API.
Reviewed by TechLogHub Engineering Team. Last updated September 18, 2026. Updated for Electric's clean-rebuild sync engine replacing the legacy version, PowerSync's expansion beyond Postgres to MongoDB, MySQL, and SQL Server, and its selective sync and Sync Streams features.
| Feature |  Electric | PowerSync |
|---|---|---|
| Sync Model | Read-path shape sync | Bidirectional replication via Sync Streams |
| Backend Databases | PostgreSQL | PostgreSQL, MongoDB, MySQL, SQL Server |
| Client Store | Local SQLite or in-memory | Client-side SQLite |
| Write Path | Your own backend API | Bidirectional, with server-side validation |
| Conflict Handling | Handled in your write path 6/10 | Managed with server authority on writes 8/10 |
| Managed Service | Available, lighter-weight | Core offering, fully managed |
| Selective Sync | Shape-based subsets | Yes, declarative streams |
| Production Maturity | Rebuilt engine, growing adoption | Production-proven |
Electric
A Postgres sync engine, rebuilt from its legacy version, that syncs subsets of a Postgres database (shapes) into local clients over a read-path model, leaving writes to your own backend API.
Pros
- Lightweight read-path sync — define shapes and Electric streams them to clients
- Rebuilt engine is simpler and more scalable than the legacy version
- Works with standard Postgres — no exotic database requirements
- You own the write path through your existing API, keeping server logic in one place
- Open-source core with a clear, focused scope
- Plays well with existing Postgres-backed stacks
Cons
- Read-focused — you build the write and conflict-handling path yourself
- Postgres only, unlike PowerSync's multi-database support
- Less of a turnkey, fully-managed offering than PowerSync
- The legacy version was discontinued, so older tutorials mislead
- Younger rebuilt engine has a shorter production track record
Best For
Postgres-backed apps that want lightweight read-path sync and are comfortable owning the write path through their own API, and teams that prefer a focused open-source engine.
PowerSync
A managed local-first sync service that handles bidirectional replication between a server database and client-side SQLite, with declarative Sync Streams, selective sync, and support for multiple backend databases.
Pros
- Multi-database — supports PostgreSQL, MongoDB, MySQL, and SQL Server
- Declarative Sync Streams define what syncs without hand-rolling replication
- Managed service means you don't operate sync infrastructure
- Bidirectional replication handles both reads and writes
- Selective sync moved past the dump-everything-on-first-connect limitation
- Generous free tier for prototyping, with a clear paid path
- Shortest path to production if your backend is already Postgres
Cons
- The managed service is the core value — self-operating is less the point
- Bidirectional sync means more moving parts than a read-only model
- Client writes require server-side validation since the client is untrusted
- Pricing scales with synced data volume and connections
- More opinionated than a minimal read-path engine
Best For
Production local-first apps that need bidirectional sync, teams on Postgres, MongoDB, MySQL, or SQL Server, and anyone who wants managed sync infrastructure rather than building it.
Read-Path vs Bidirectional Is the Core Split
Electric's rebuilt engine focuses on the read path: you define shapes — subsets of your Postgres data — and it streams them to local clients, while writes go through your own backend API. PowerSync handles replication in both directions, so client writes flow back to the server through its infrastructure. The trade is control versus completeness. Electric keeps your server-side write logic in one place you already own; PowerSync gives you a complete sync loop without building the write path, at the cost of more moving parts.
The Untrusted-Client Problem Doesn't Go Away
Both engines face the same fundamental constraint: the client is an untrusted environment, so writes propagated back to the server database need validation and authority checks. PowerSync handles this within its managed bidirectional model, with the server as the authority on writes. Electric's design pushes it into your API, which is more work but keeps validation in code you control. Neither eliminates the problem — local-first sync is hard precisely because reconciling untrusted client writes with a server source of truth is genuinely difficult.
Backend Flexibility Favors PowerSync
Electric is Postgres-only, which is fine if that's your stack and a hard stop if it isn't. PowerSync expanded to PostgreSQL, MongoDB, MySQL, and SQL Server, which matters for teams not on Postgres or running a mixed environment. If your backend is already Postgres — and if you're on Supabase, it is — both are in play and the decision comes down to read-path simplicity versus managed bidirectional convenience. Off Postgres, PowerSync is often the only one of the two that fits.
Respect How Hard Local-First Actually Is
The recurring lesson from teams adopting local-first is that the distance between the pitch and production reality is wide. What sounds like storing a few records locally and syncing them back becomes layers of conflict resolution, IndexedDB corruption from botched migrations, and more sync code than product code. Both engines exist to close that gap, and the more managed option generally gets you to production faster. Prototype the sync layer early with real offline and conflict scenarios before committing — the happy path always works; the edge cases are the project.
Verdict
Choose PowerSync when you want a production-proven, managed sync engine with bidirectional writes and the flexibility to sit on Postgres, MongoDB, MySQL, or SQL Server — it has the shortest path to production, especially on Postgres. Choose Electric when you want a lightweight, focused read-path engine on Postgres and are happy owning writes through your own API. The honest baseline: local-first is genuinely harder than it looks, so lean toward the more managed option unless you have a reason not to.