Ferrynote
A small notes app that works fully offline, syncs when it can and fits in an 18 KB core.
client
—
role
Author
year
2025
stack
TypeScript · React · IndexedDB
01 / problem
I wanted a notes app that opens instantly on a train with no signal and does not need an account. Most apps I tried that promised offline use were either heavy or lost edits when two devices changed the same note.
02 / approach
Ferrynote stores everything in IndexedDB, renders with React and syncs through a tiny merge layer that keeps both versions of a conflicting paragraph instead of picking one. The service worker caches the shell, so the app opens with no network at all.
03 / outcome
The core bundle is 18 KB gzipped and the app works offline from the first visit. It is open source, has a small and friendly group of users, and is now my reference for how I build PWAs for clients.
Offline
Works with no connection
18 KB
Gzipped core bundle
