The Architecture Of Local-First Web Development

Local-first web development is a data architecture where client devices hold primary copies of data and sync with servers in the background, fundamentally different from offline-first and PWA approaches.

• •Local-first distinguishes from offline-first, PWA, and cache-first by treating the client as a node in a distributed system with its own database rather than a thin view requesting permission
• •Best suited for user-generated data like note-taking, document editing, collaborative design, and field apps; inappropriate for server-generated data, strong transactional consistency requirements, and massive datasets
• •Implements Git-style replication where each client holds data replicas, enabling instant local writes and background sync without loading states or optimistic update logic
• •Uses SQLite compiled to WebAssembly with Origin Private File System (OPFS) for persistent, queryable client-side database replacing localStorage and IndexedDB