Local-first software
Local-first software keeps data and core functionality on a user’s device, syncing with other devices only when needed.
Quick answer
Local-first software keeps the primary working data and core functions on the user’s device. It may sync with other devices, while aiming to remain useful when a server is unavailable. (Ink & Switch, “Local-First Software”)
How is local-first different from offline-only software?
Offline-only software never synchronises. Local-first software can synchronise when a connection is available while keeping a usable local copy. The exact design varies by product. (Ink & Switch, “Local-First Software”)
What should you check?
Look for where the primary copy is stored, whether sync is optional, what metadata leaves the device, how conflicts are resolved, and whether you can export or recover your data. Local does not automatically mean encrypted or private from other users of the same device.
Can a browser tool be local-first?
A browser tool can download its code once and process later inputs on-device. Inspect network requests while entering sample data, then test whether the core function works after the page loads and the device disconnects.