Databases for Local-first sync

HTTP/JSON document database built around multi-master replication and offline-first sync.

Tiny memory-mapped B+tree with ACID transactions and lock-free readers; reached 1.0 in 2026.

Real PostgreSQL compiled to WebAssembly: an embeddable Postgres for browsers, Node, Bun and Deno.

Google's original small, fast LSM key-value library, now in limited-maintenance mode.

The browser's built-in transactional object store, and the storage layer under most web local-first libraries.

Read-path sync engine that streams partial replicas of Postgres to clients over plain HTTP.

Turso's open-contribution SQLite fork with native vectors, a network server and embedded replicas.

Decentralised, offline-first graph database that syncs peer-to-peer in JavaScript.

The most popular IndexedDB wrapper, with live queries and an optional Dexie Cloud sync service.

Ground-up Rust rewrite of SQLite with concurrent writes, async I/O, CDC and vector search.

Sync engine that keeps on-device SQLite in sync with Postgres, MongoDB, MySQL or SQL Server.

JavaScript database for browsers and Node that speaks the CouchDB replication protocol.

Query-driven sync engine: clients run ZQL locally against a Postgres-backed cache for instant UIs.

Pure-JavaScript in-memory SQL engine for browsers and Node.js that queries arrays, JSON, CSV and Excel files.

Reactive local-first NoSQL database for JavaScript with pluggable storage and replication.

Full-stack syncing database for TypeScript apps; development has stalled since 2025.

Tiny type-safe local JSON database for Node, Electron and the browser using plain JavaScript.

Tiny reactive in-memory store for tables and values, with persisters and CRDT sync.

Lazy-loading reactive database for React Native and React apps, built on SQLite.

Event-sourced local-first data layer: reactive SQLite on the client, rebuilt from a synced event log.

Immutable in-memory database with Datomic-style Datalog queries for Clojure, ClojureScript and JavaScript.

Local-first database with built-in sync, permissions and edit history, being rebuilt as a relational Jazz 2.

Local-first TypeScript platform: SQLite on each device, end-to-end encrypted sync through relays.

Pure-Rust embedded key-value store: copy-on-write B-trees, ACID, and a stable file format.

Managed, distributed SQLite with pub/sub, edge functions and CRDT sync to on-device databases.

Ambitious lock-free embedded Rust database whose 1.0 rewrite has stalled in alpha.

Serverless peer-to-peer database on IPFS and libp2p using Merkle-CRDT logs.

Client-side sync framework for instant web UIs; now free, open source and in maintenance mode.

Edge-native document database that syncs peer-to-peer over Bluetooth, P2P Wi-Fi and LAN without internet.

Objective-C object database with Git-like branching, tree-structured undo and semantic merging built in.

The in-process SQL engine that ships in every phone, browser and OS: one file, zero servers.

Dependency-free SQLite extension for vector search that runs anywhere SQLite does, including WASM.

Rust multi-model database (documents, graph, vectors, live queries) that runs embedded, in WASM or clustered.

Embedded Datalog database blending relational, graph and vector queries; dormant since 2024.

Managed SQLite-compatible cloud for database-per-tenant apps, with embedded replicas and offline sync.

Embedded JSON document database with SQL++ queries, vector search and sync to Couchbase.

Single-threaded stateful actors at the edge, each with its own strongly consistent SQLite store.