Calibre Sync for Android & iOS

[PeterT]

And another new release; now includes preliminary support for TeraBox

[dizzy274]

Hi
Since the TeraBox release it's not closing correctly for me. Just hangs on blank screen.

Ian.

[nephtys59]

The new update didn't fix the covers issue with Pcloud, though ...

[dizzy274]

So many updates!! My problem with CS not shutting down correctly has been fixed.

[Incanus]

Hello:

I'm running Calibre Sync v6.83 on my Android 16 One UI 8.0 Samsung Galaxy A54 5G.

Whenever I try to open an ebook from Calibre Sync, my KOReader v2026.03 will show me another e-book, that was previously opened using KOReader's file manager.

Calybre Sync will work fine with another reader software, such as MoonReader.

Is this an Android, Samsung, Calibre Sync or a KOReader issue?

Has anyone experienced the similar problem and solved it: how?

Awaiting your kind reply,

[CardcaptorRLH85]

Originally Posted by Incanus

Hello:

I'm running Calibre Sync v6.83 on my Android 16 One UI 8.0 Samsung Galaxy A54 5G.

Whenever I try to open an ebook from Calibre Sync, my KOReader v2026.03 will show me another e-book, that was previously opened using KOReader's file manager.

Calybre Sync will work fine with another reader software, such as MoonReader.

Is this an Android, Samsung, Calibre Sync or a KOReader issue?

Has anyone experienced the similar problem and solved it: how?

Awaiting your kind reply,

It's an Android problem. I'm having the same issue on my Pixel 10 Pro Fold running Android 17 QPR 1 Beta 1 but not on my Galaxy Tab S7+ running Android 13 (both using Moon+ Reader). Something changed in the last few versions of Android that doesn't allow Calibre Sync to directly open files in your reader of choice. Does anyone have a workaround for this?

[jbusnengo]

Originally Posted by CardcaptorRLH85

It's an Android problem. I'm having the same issue on my Pixel 10 Pro Fold running Android 17 QPR 1 Beta 1 but not on my Galaxy Tab S7+ running Android 13 (both using Moon+ Reader). Something changed in the last few versions of Android that doesn't allow Calibre Sync to directly open files in your reader of choice. Does anyone have a workaround for this?

Are you sure that it's an Android issue? I have no problems opening books from Calibre Sync in FBReader. I'm using a Pixel 6 with Android 16.

[Incanus]

Originally Posted by jbusnengo

Are you sure that it's an Android issue? I have no problems opening books from Calibre Sync in FBReader. I'm using a Pixel 6 with Android 16.

As you may read on my original post, I've also had various results depending on the reader app.

[jbusnengo]

Originally Posted by Incanus

As you may read on my original post, I've also had various results depending on the reader app.

I did see that. I was responding to CardcaptorRLH85's blanket assertion that it was Android "that doesn't allow Calibre Sync to directly open files in your reader of choice." If the issue occurs with one app but not another, isn't that app the logical first place to look?


If you try to open an epub from your device's file manager app, does it give you the same problem? If so, I'd think that would make it unlikely that the problem is with Calibre Sync.

[Incanus]

Originally Posted by jbusnengo

If you try to open an epub from your device's file manager app, does it give you the same problem?

Yes: I just checked and it appears that I can't open an ebook file from my file manager app using KOReader as the reading app.

Originally Posted by jbusnengo

If so, I'd think that would make it unlikely that the problem is with Calibre Sync.

You're quite right. It could be a problem of the file manager app and/or the KOReader app (permissions or something similar).

Thanks for your help and insight!

[vishae]

I'm wondering if anyone is experiencing the same issue:

- Calibre Sync v6.9.1 on iOS (but it was happening in earlier version)
- Calibre 9.9, running on a Synology NAS
- Library size of 704 books (mix of epubs and cbz)

I add my Calibre Library to Calibre Sync using Content Server.
Calibre Sync grabs all my book metadata, shows all the covers etc
When I need to download the book's epub, I can do that with no problem.

I add a new book to Calibre Library, then I go to Calibre Sync and pull down to refresh the library. Nothing happens. The sync icon doesn't spin, and the book list doesn't update.
I look at the library info, the sync date hasn't changed from the day I added the library.

I click the "sync" button in Library Info, and nothing moves (icons don't spin) or changes (library stuck at 704 books).

I delete the library and re-add it to Calibre Sync. The library loads up with my new book (705 books), cover loads fine, epub downloads fine.

Add another book to the Calibre library, try to sync on Calibre Sync -- again, nothing.

[dunhill]

Originally Posted by vishae

I'm wondering if anyone is experiencing the same issue:

- Calibre Sync v6.9.1 on iOS (but it was happening in earlier version)
- Calibre 9.9, running on a Synology NAS
- Library size of 704 books (mix of epubs and cbz)

I add my Calibre Library to Calibre Sync using Content Server.
Calibre Sync grabs all my book metadata, shows all the covers etc
When I need to download the book's epub, I can do that with no problem.

I add a new book to Calibre Library, then I go to Calibre Sync and pull down to refresh the library. Nothing happens. The sync icon doesn't spin, and the book list doesn't update.
I look at the library info, the sync date hasn't changed from the day I added the library.

I click the "sync" button in Library Info, and nothing moves (icons don't spin) or changes (library stuck at 704 books).

I delete the library and re-add it to Calibre Sync. The library loads up with my new book (705 books), cover loads fine, epub downloads fine.

Add another book to the Calibre library, try to sync on Calibre Sync -- again, nothing.

I have it set to update the library when I open Calibre-Sync, but swiping down does nothing. It updates on startup (I'm on Android).

[jbusnengo]

As far as I can tell, updating the library now works in the background, and there's no on-screen indication that the update is happening. In my case (Android 16 on Pixel 6 with a locally stored library of 4783 books that I use other software to sync), the update will show a few minutes after I tap on the refresh button. I don't have any books to add to my library at the moment, so I can't time it, but IIRC, it takes somewhere around 3-4 minutes for me.

I do leave Calibre Sync as the foreground app while it's updating. I haven't been brave enough to try switching to another app while waiting. My phone can be a bit overeager to close background apps.

[vishae]

Originally Posted by dunhill

I have it set to update the library when I open Calibre-Sync, but swiping down does nothing. It updates on startup (I'm on Android).

I already have "Keep libraries up to date, sync at application launch" checked, and that doesn't make a difference

Originally Posted by jbusnengo

As far as I can tell, updating the library now works in the background, and there's no on-screen indication that the update is happening. In my case (Android 16 on Pixel 6 with a locally stored library of 4783 books that I use other software to sync), the update will show a few minutes after I tap on the refresh button. I don't have any books to add to my library at the moment, so I can't time it, but IIRC, it takes somewhere around 3-4 minutes for me.

I do leave Calibre Sync as the foreground app while it's updating. I haven't been brave enough to try switching to another app while waiting. My phone can be a bit overeager to close background apps.

I leave Calibre Sync open the whole time, but nothing is loading, there's no progress bar, no spinny wheel, so I don't know how long I have to keep the app open for.


I was wondering if there was a Github for me to lodge an issue ticket, but I guess I can just email the developer.

[jbusnengo]

Originally Posted by vishae

I was wondering if there was a Github for me to lodge an issue ticket, but I guess I can just email the developer.

I already did and got a positive response. It sounds like they're planning on animating the icon.