Signals for instant UI updates, plus real-time sync when you need it.
SignalDB is a reactive JavaScript database powered by signals for instant UI updates. Works with any framework, with adapters for Angular, Solid.js, React, Vue, and more.
Two clients keep a shared list in sync automatically. Toggle offline to pause push/pull, create edits on either side, and watch field-level conflicts resolve while the server view updates below.
Client A
Client B
Server
Event log
SignalDB is an open-source, reactive local JavaScript database. Your app keeps its data in collections on the client, queries them with a MongoDB-like API, and gets results that update automatically through the signals of the framework you already use. Data is persisted locally (IndexedDB, OPFS, localStorage) and synchronized with any backend in the background.
import { Collection } from '@signaldb/core'
import createIndexedDBAdapter from '@signaldb/indexeddb'
const posts = new Collection({
persistence: createIndexedDBAdapter('posts'),
})
posts.insert({ title: 'Hello SignalDB', published: true })
posts.find({ published: true }).fetch() // reactive inside your framework's effectsA client-side database like SignalDB is a good fit when:
SignalDB focuses on signal-based reactivity, a familiar MongoDB-style query API and backend-agnostic sync. See the JavaScript database comparison for how it relates to RxDB, Dexie.js, PouchDB, WatermelonDB, TinyBase and TanStack DB, or read JavaScript Signals Explained for the reactivity model behind it.