You do not always have a solid internet connection when you need to log a dose. Maybe you are out and about, in a basement flat with patchy signal, travelling, or simply in aeroplane mode. If your tracking app stops working when the connection drops, your data gets gaps — and gaps make your stock estimates unreliable.
Offline tracking solves this. Here is why it matters for UK medical cannabis patients and what to look for.
Why offline matters for cannabis tracking
Medical cannabis tracking depends on consistency. Every missed entry affects your stock balance, your burn rate, and your prescription countdown. A single missed dose might not matter much, but a pattern of missed entries — because the app did not work when you were out — adds up. Before you know it, your estimated balance is wrong, and you are uncertain about how much you actually have left.
Offline support means you can log a dose anywhere, anytime, regardless of your connection. The entry is saved locally on your device. When you are back online, it syncs automatically with the server. You do not have to remember to log it later, and you do not lose the data.
For UK patients, this is particularly relevant. Mobile signal in the UK is not universal — rural areas, older buildings, and even some urban locations can have poor coverage. If your tracking app requires a constant connection, its usefulness is limited to wherever you happen to have signal.
How offline tracking works (technically)
Offline-first apps use a technique called local-first storage. When you log a dose, the entry is written to your device's local storage (IndexedDB in the browser) and queued for synchronisation. When the app detects a connection, it sends the queued entries to the server and confirms they have been stored.
This approach is common in Progressive Web Apps (PWAs) — web applications that can be installed to your home screen and behave like native apps. PWAs can use Service Workers to cache the app shell and manage offline data, providing a reliable experience even without a connection.
What to look for in an offline-capable tracker
Not every app that claims offline support actually delivers it reliably. Here is what to check:
- Does it work in aeroplane mode? The easiest test: put your phone in aeroplane mode and try to log a dose. If the app freezes, shows an error, or refuses to save, offline support is not real.
- Does it sync automatically? When you come back online, do your entries sync without you having to do anything? Manual sync is easy to forget.
- Does it handle conflicts? If you log on two devices while offline, what happens when both come online? A good offline system handles this gracefully.
- Is it a PWA? Installable PWAs are generally better at offline support than standard websites because they use Service Workers to manage caching and synchronisation.
The alternative: what happens without offline support
Without offline support, you have two options when the connection drops — neither of them good:
- Remember to log it later. This works about as well as you would expect. By the time you are back online, you have forgotten the exact amount, or you get busy and forget entirely.
- Use a different tool. Some patients keep a paper backup or a notes app for offline doses, then transfer them later. This doubles the work and introduces transcription errors.
Both options create friction, and friction kills consistency. The best tracking tool is the one you actually use — and offline support removes one of the biggest barriers to consistent logging.
How Grams Left handles offline tracking
Grams Left is a PWA — install it to your home screen from your browser and it works offline by design. Log a dose anywhere, even with no signal. Your entries are saved locally and sync automatically when you are back online. No data lost, no need to remember, no double-entry.
Offline tracking, like the rest of the core tracker, is free forever with no card required. A tracker that only works when you have signal is really only a tracker for the times you happen to be online; an offline-first one is there whenever you actually take a dose.