Offline-first: apps that keep working without signal
An offline-first app is designed on the assumption that the network will often be missing. Everything you create is saved on the device first and sent to the server later, so a lost connection slows the exchange of data but does not stop the work.
Offline-first versus an offline mode
Many apps add an offline mode on top of an online design: you can read what was cached, but most actions wait for signal or fail. An offline-first app turns that around: work happens in the local copy on the phone, and the server is where the copies meet. In practice that means three things:
- Maps, plans and lists are downloaded before the team leaves coverage.
- New records go into a local queue and are sent when a link appears, in order.
- When two people edit the same thing apart, the app merges what it safely can and shows the rest as a conflict.
A search in a valley without coverage
A search team walks into a valley with no mobile signal. Each phone already holds the offline map, the sector boundaries and its own tasks. Over three hours the team logs two findings with photos, closes one task and records its tracks. None of it reaches headquarters until the team climbs back to the ridge at 17:10, when the queue empties in under a minute. On the timeline the first finding appears at 14:32, when it was made, marked as received late. Our missing-person search checklist includes downloading packs before deployment.
How Sinkaos is built offline-first
Mission packs
Each phone carries offline maps of the area, the plan, its tasks, the team list, documents and the operation keys.
Everything works offline
Messages, reports, incidents, tasks, map edits, tracks and forms are created without signal and sent when possible.
Two clocks
When something happened and when it became known are kept apart, so late reports land at the right time.
No silent overwrites
Edits made apart are merged where safe and shown to you where they conflict.
Local field server
A laptop or small box runs the operation over local Wi-Fi with no internet and syncs with other nodes later.
Testing an offline-first app, and its limits
What cannot work offline, even in an offline-first app?
How do I test whether an app is really offline-first?
Do offline maps use a lot of storage?
Try it on your next operation.
Early access is free. We set up the first operation with you and stay close while you use it.