A technician records work in an area with poor signal. The screen says “saved,” but the office has not received it. Offline behavior needs clear wording and a tested synchronization plan.
Define the local task
Choose what information must be available on the device and which actions can wait. Reading a job brief, drafting notes and confirming a financial action may have different requirements.
Browsers offer storage mechanisms such as IndexedDB, but local storage capability alone does not make an application reliably offline. Device behavior, storage limits and the synchronization design need review.
Show pending work
Let the user distinguish a local draft, a queued update and a server-confirmed result. If someone else changed the record while the device was offline, use an agreed conflict path rather than silently overwriting work.
Test lost connectivity during entry and during upload, then reconnect. Check repeated attempts and large attachments on the actual supported devices.
Bring the field conditions and essential tasks to the project brief. Offline support is a meaningful part of scope, with device testing and operating guidance, rather than a label added because the application can open a cached page.
Agree what staff do if a device is lost before pending work synchronizes. The operating guide should describe the limit rather than imply that a local save is already recoverable centrally.