Offline reading
Tsumiru can keep chapters on your device so you can read them with no connection to your Suwayomi server. The sources still come from Suwayomi; offline reading stores the pages on your device, so the app doesn't need to reach the server while you read.
This is separate from server-side downloads. A server download tells your Suwayomi server to fetch a chapter and keep it on the server. An offline download copies that chapter onto this device. The two work together: a chapter has to be downloaded on the server before it can be saved to your device, and if it isn't yet, Tsumiru queues the server download for you automatically.
Where it works
Offline reading is available on the Android, iOS, Windows, macOS, and Linux apps. It is not available on the web app, which always reads from the server.
Getting chapters onto your device
There are two ways to save chapters offline.
Keep a whole series offline
On a series page, tap Offline (next to In library) to choose a rule. Once chapters are saved it reads On device. Tsumiru then keeps the matching chapters on your device automatically. After every library update it fetches the new chapters for each kept series (asking the server to download them first when needed) and removes older ones the rule no longer covers:
- Keep next 5 / 10 / 25 unread: a rolling buffer of upcoming chapters, refilled as you read.
- Keep all unread: every unread chapter.
- Keep all chapters: every chapter in the series.
The series page shows its current keep mode, so it's clear why chapters are being kept. You can also keep several series offline at once: select them in the library, choose Keep offline, and pick how much of each to keep.
To stop keeping a series offline, open the same sheet and choose Remove all (this series), which clears the rule and deletes that series' chapters from the device. To drop the rule but keep the files, use Downloads → On device, where each series offers Stop keeping (keep files) or Stop keeping & delete files. Your server library is untouched either way.
Save individual chapters
On the chapter list, each downloaded chapter has a Save to device button. Tap it to store just that chapter offline; tap it again (it becomes a filled pin) to remove the device copy. Chapters you save by hand are pinned: they stick around regardless of the series' keep rule and are never removed by the storage limits below.
Reading the chapter list
Each chapter row can show two indicators, one for the device and one for the server:
| Indicator | Meaning |
|---|---|
| Save icon | On the server, not yet on this device; tap to save offline |
| Spinner | Saving to this device (fills in as pages arrive) |
| Filled pin | Saved on this device; tap to remove the device copy |
| Checkmark | Downloaded on the server |
So a chapter that's fully available offline shows both a pin (on your device) and a checkmark (on the server). Deleting the server download also removes the device copy.
Reading when the server is offline
When Tsumiru can't reach your server, it falls back to what's stored on the device:
- Your library shows the series you have saved offline, with their covers.
- Opening a saved chapter reads the pages straight from the device, no network needed.
- Your reading progress is saved locally and synced back to the server automatically the next time you reconnect.
- Your category tabs work offline too, and you can still hide or show them. A change made offline stays on this device only: it isn't sent to the server, and the server's own setting comes back at the next sync.
The switch happens on its own. If the library is still trying to connect, a View offline button appears on the loading screen whenever there are downloads to show. Tap it to go straight to your downloaded library instead of waiting.
Chapters you haven't saved offline aren't available until the server is reachable again.
To see only what you can read offline, open the library filter and turn on On device.
Managing storage
The Downloads screen has two tabs: Server (what your Suwayomi server is downloading) and On device (what's stored locally). Open Downloads → On device to see everything on this device: total storage used, and a row per series with its chapter count and size. From a series page you can Delete on-device downloads for that series, and individual chapters can be removed with their pin button.
You can pause and resume the on-device download queue from the same screen, so a large batch doesn't have to run all at once.
To configure offline storage, go to Settings → Downloads and open the On device tab:
- Storage used: how much space your offline chapters take up.
- Remove all downloads: clears every offline chapter from this device in one step (your server library is untouched).
- Simultaneous downloads: how many pages download at once (1–8, default 2). Lower it on a slow or metered connection.
- Download over Wi-Fi only: on by default, so background downloads don't spend mobile data. Turn it off to allow downloads on any connection.
- Download new chapters in the background (Android): fetch new chapters for series you keep offline without opening the app.
Categories can also download on their own: pick which ones under the download settings, and their new chapters are saved without you asking each time.
Keeping storage in check
Three optional safety nets keep offline storage from growing without limit. All are off by default, and none ever removes chapters you've pinned by hand:
- Delete finished chapters while reading: remove an auto-kept chapter once you finish it, so storage doesn't pile up. The delete waits until you close the reader, so a chapter never disappears mid-session. Set it per device or for the server under Settings → Downloads.
- Limit offline storage: set a ceiling (default 2 GB). When you go over it, the oldest auto-kept chapters are removed first.
- Auto-remove old downloads: delete auto-kept chapters older than a set age (default 30 days).
Downloading in the background
On Android, offline downloads keep running when Tsumiru is in the background or closed. A "Downloading chapters" notification shows progress (and lets you keep an eye on a long batch without leaving the app open); it clears itself when the batch finishes, and a Downloads complete notification lets you know. Turn download notifications on or off under Settings → Notifications (see Notifications).
If your connection drops mid-batch, downloading pauses and waits for the network, then resumes on its own when you're back online, picking up where it stopped. The first time you download in the background, Android may ask you to exempt Tsumiru from battery optimization so it doesn't pause long batches.
On desktop (Windows, macOS, Linux), downloads continue as long as the app is running, including when its window is minimized.