Local-first sync engines

A Dexie Cloud alternative for apps that have no accounts

Both start from IndexedDB in a browser and end with the same data on another device. If your app is built on Dexie, both are one dependency away.

How s3nd works Dexie Cloud

What Dexie Cloud is

In its own terms.

A sync service for Dexie.js, the IndexedDB wrapper. Add the addon, point it at a Dexie Cloud database, and the local tables sync continuously, with authentication, per-object access control and realtime updates. Hosted by the Dexie team, with a free tier and paid plans, and an on-premise option.

Side by side

Where they part ways.

	s3nd	Dexie Cloud
What it is	A CLI, a library and React hooks over your own S3 bucket	Continuous sync service for Dexie.js
Where the data lives	Your bucket: S3, R2, MinIO, Scaleway, Wasabi	Dexie Cloud’s servers
Both ends online at once	No. The code is redeemed later, until it expires	No
From inside your web app	Yes, through one route on your server	Yes, that is the point
Accounts	None. The code is the whole handshake	Required
Hosting	Your bucket, plus your server when a browser takes part	Hosted by Dexie; an on-premise option is offered
Price	Free. You pay your storage provider for a few objects that expire	Free tier, paid plans
License	MIT	Proprietary service; the client addon is open source

The differences

What actually changes.

Continuous sync versus a snapshot

Dexie Cloud syncs every change, both ways, all the time, and merges. s3nd takes a snapshot of the whole database and carries it across once, or rewrites a per-user backup with a conditional write. It does not merge; your app does, when it wants to.

Accounts versus a code

Dexie Cloud identifies users, which is how it knows whose data to sync and who may see it. s3nd has no notion of a user: a code is the whole handshake, which is exactly what a local-first app without sign-in needs.

Their service versus your bucket

Dexie Cloud is a backend the Dexie team runs for you. s3nd is a few small objects in a bucket you already own, with no service in the middle.

Dexie versus anything

Dexie Cloud needs Dexie. s3nd stores whatever your app exports, from Dexie, raw IndexedDB, SQLite in WASM, or a plain object.

The decision

Pick the one that fits.

Pick Dexie Cloud when

You use Dexie and want continuous multi-device sync with sharing and permissions.
Realtime collaboration between users.
A hosted backend is fine, and welcome.