Offline Data

Flipnem keeps the decks you study on your device, so you can keep studying without a connection — on a plane, the subway, or anywhere the network drops.

What works offline

Once you've opened a deck while online, it's cached locally and available offline:

• Studying — cards you've loaded render and advance with no connection.
• Answering — ratings you give while offline are saved on the device and uploaded automatically the next time you reconnect.
• Media — images and audio for the cards you've loaded are cached too.

The app itself (its pages and code) is cached as well, so it launches and reloads offline.

What doesn't work offline (yet)

• Decks you've never opened online — nothing is cached for them, so they can't be studied offline until you've opened them at least once while connected.
• Editing — adding, changing, deleting, or reordering cards and decks needs a connection. Offline editing is planned for a future update.
• Importing decks.

How your device stores it

Flipnem uses your browser's built-in local storage (IndexedDB for card data, the Cache API for media and the app itself). This works in any modern browser with no setup — it's what makes offline study possible, and you do not need to install anything for it to work.

By default, though, this storage is best-effort: it works, but the browser is allowed to clear it when the device runs low on disk space, evicting whatever it thinks you're least likely to need. On a desktop with free disk this rarely happens. It's more likely on phones — and especially on iPhones and iPads, where Safari clears a non-installed site's stored data after about a week of not visiting it.

Keeping your offline data protected

To guarantee your cached decks and media aren't cleared, install Flipnem as an app:

• iPhone / iPad — in Safari, tap Share → Add to Home Screen.
• Desktop / Android — use the install button in your browser (see the PWA question in the Support / FAQ section on the home page).

Installed apps get persistent storage — the browser won't evict their data under space pressure, and only clearing the app's data will remove it. This is the difference between "cached, but the browser might reclaim it" and "kept until you say otherwise."

You can see how much space Flipnem is using — and, when running as an installed app, turn on protected storage — under Settings → Offline Data.