Last updated: 17th January 2024

What’s New

Calibre Sync v6.0.0+ support multi-languages. Please leave your feedbacks about language translations so that we can improve further.

Calibre Sync v5.1.0+ support two-way sync Read/Unread status for Content server libraries.

Calibre Sync v5.0.0+ support full text search, available for Calibre v6.0+ libraries .

Calibre Sync v4.5.0+ support iCloud Drive, exclusive to iOS platform.

Calibre Sync v4.0.0+ support MEGA.

Calibre Sync v3.10.0+ support syncing Read/Unread from Calibre custom columns see more.

Calibre Sync v3.9.0+ support multiple library formats see more.

Calibre Sync v3.8.0+ support USB removable storage on Android.

Calibre Sync v3.6.0+ support Calibre-Web OPDS server.

Calibre Sync v3.5.0+ has home widget for recently downloaded books.

Calibre Sync v3.4.0+ has marking books read feature.

Calibre Sync v3.3.1+ supports iOS platform.

Calibre Sync v3.2.0+ supports Google Drive.

Calibre Sync v3.1.0+ supports Send to Kindle.

Calibre Sync v3.0.0+ supports Wireless device connection.

Calibre Sync v2.4.0+ allows users to write notes about their books.

Calibre Sync v1.14.0+ also supports Calibre Content Server.

Calibre Sync v1.12.0+ also supports WebDav servers.

Calibre Sync v1.10.0+ also supports Nextcloud and OwnCloud.

Calibre Sync v1.6.0+ also supports local libraries on sdcard.


  • Available on both iOS and Android
  • Full text search 🌟
  • Unlimited libraries on most popular personal cloud services: Google Drive, Dropbox, OneDrive, Box, pCloud, MEGA, iCloud (iOS) NextCloud, OwnCloud and WebDav.
  • Wireless device connection
  • Send to Kindle
  • Switch between libraries across multiple accounts
  • Search books across all of your libraries
  • Pull, Refresh or Remove a library from Calibre Sync
  • View your library statistics
  • Share book details
  • Download the book for reading
  • Email or share a copy of the book
  • View your books list in List, Grid, or Carousel layouts
  • Filter books on authors, series, tags, publishers, or formats and even in custom columns
  • Search books by title, author, publisher, even in comments and custom columns
  • Local storage and sdcard support
  • Material design, customizable color & dark theme and many more in the pipelines …



  • New feature! Select all and select none for filters of a column (e.g. authors, tags, …) in library filter screen.


  • New feature! Virtual views and save filters are able to remember sort and view layout, this can be enabled in Settings.


  • New feature! Advanced sort with multiple columns.


  • Android: fix permission issue when downloading books with Smart Device.


  • New feature! Searching in library filters now supports languages with accents and diacritics.


  • New feature! Refresh view in Smart Device to clean books that are removed.
  • Android: fix permission issue when downloading books.


  • New feature! Libraries on left sidebar can now be filtered if you have more than 7 libraries.


  • Improve Smart Device stability and add more information about wireless connection.


  • New feature! Library filters can now be saved, please check this out under virtual views section.
  • New feature! Virtual views and saved filters can be sorted alphabetically or pin/unpin.
  • New feature! When books with only one format, READ will open the format directly.


  • New feature! Long press on libraries in side bar to pin/unpin the library.


  • Improve UI when moving download/inbox directory or downgrade/upgrade library formats.


  • New feature! Settings to not download covers in auto sync.
  • Improve default listing unread books in library view in auto sync.


  • New feature! Double tap a book in Grid view to open quick actions for downloading and reading the book.
  • New feature! Alphabet group view supports sorting by author and series.


  • New feature! Smart Device library can now be deleted.


  • New feature! Multilanguage support.


  • Fix issue of displaying publication dates before 1970.
  • Improve Two-way sync Read information for Content Server libraries.


  • Box service integration improvement.


  • Keeping device screen on while downloading covers to avoid operating systems sleeping the app.


  • Fix search UI for black/white colour theme.


  • Improve UI for black/white colour.


  • More colours to choose in theming, black/white can be used to display better on e-ink devices.


  • Improve date display for Read/Unread status.


  • Fix author name display to be consistent with Calibre.


  • New feature! Downloaded/Not downloaded and Read/Unread can now be chosen in library filter page.


  • Android: Predefined book cover location setting.


  • Fix issue with email client on Android 13 for Send to Kindle feature.


  • New feature! Two-way sync Read information for Content Server libraries.


  • Performance improvement for large libraries with OneDrive and Dropbox services.


  • Performance improvement for Calibre-web and Content Server services.


  • New feature! Full text search support, more details can be found here.


  • iOS: Fix iCloud sync issue.


  • iOS: Improve iCloud service integration.


  • iOS: Improve iCloud initial loading time.


  • Fix issue on WebDAV integration.


  • Setting for default listing unread books in library view.


  • iOS: Improve performance for iCloud service
  • Sort author by surname in filter page


  • Stability improvement for pCloud services.


  • New feature! Quicker way to download missing covers, from Library popup menu items.


  • Android 13: fix permission issue.
  • Add option to request for app permissions in Settings page.


  • Improve sorting behaviour, now similar to Calibre desktop.
  • Allow to select libraries manually for Share OneDrive service.


  • Further batch download covers improvement.


  • Batch download covers improvement.


  • Improve search performance.


  • Support for shared folders in Dropbox.
  • Stability improvement for syncing libraries.


  • Performance improvement for MEGA service.


  • Improve integration with Dropbox.


  • Improve integration with OneDrive share folders.


  • iOS: improve details for iCloud service.


  • Android: resolve issue of MEGA login that causes unresponsive UI.


  • Stability improvement for MEGA services.


  • New feature! iCloud service support for iOS platform.


  • New feature! Support share folders for MEGA services.


  • Improve integration with MEGA service.


  • UI improvement: Shuffle books option is back.


  • UI improvement: Open a random book instead of shuffling.
  • UI improvement: Setting to hide share buttons.
  • UI improvement: Big read button in book view.
  • New feature!: alphabet group view.


  • Android: fix issue with downloaded books cannot be opened in widgets.


  • New feature! Send to Kindle action for multiple selected books.
  • Improve library synchronisation functionality.


  • New feature! True black theme and more customisation for look and feel.


  • New feature! MEGA cloud service support.
  • New feature! You can now use already logged in accounts to sync new libraries.
  • Accessibility setting to move clear all filters button to top bar.


  • UI improvement: improve list downloaded/not downloaded.


  • Android: add export book cover option.


  • Manual folder browser for selecting libraries in Dropbox.


  • GUI improvement: disable error loading cover images.


  • Improve filter for custom columns of content server libraries.


  • Option to disable/enable predictive search, i.e not showing search results while typing, this can be toggled in Settings page.
  • Touch on series in library list view can now show books from the same series.


  • Better support in search and sort functions for languages with accents and diacritics. This option, namely unicode normalisation, can be enabled/disabled in Settings page.


  • Add option in Settings to disable/or enable loading book ratings for Calibre-web libraries.
  • Tags in Smart Device books can now be used to as filters.


  • Improve theme for search history.


  • Loading books indicator when loading library metadata for Calibre-web and Content Server.


  • Search results can now be saved as virtual views.
  • History for search boxes, limit at 15 entries.


  • Android: add clean temporary files functionality in Smart Device.
  • GUI improvement.


  • New batch actions menu group, added two new actions for marking selected books unread/read.
  • Show tags in detailed list view, this can be enabled/disabled in settings.


  • Improve compatibility with Box service for versioning files.


  • Improve compatibility with Box service for downloading book formats.


  • Add filter for listing not downloaded books.
  • Add epub into supported formats for Send to Kindle.


  • Sync book read information support for Calibre-Web.


  • Sync book read/unread information from Calibre custom columns. You can checkout this feature from Library Info.


  • Improve series index number format.


  • Improve compatibility with multiple library formats.


  • Android: dark theme for home widgets, can be enabled/disabled in Settings.


  • Feature: allow multiple library format (V1 or V2) for downloaded book filenames, please check out this feature in Settings. You can then upgrade/downgrade your library formats to V2/V1 from Library Info.


  • iOS: release for iOS 10.


  • Android: support for libraries on USB removable storage.


  • Improve compatibility with custom columns.


  • Fix issue of Calibre-web downloaded books cannot be opened when filenames containing reserved characters.
  • Fix visibility issue of Read marker when syncing libraries.


  • Handle custom identifiers.


  • Android: fix download for mobi files on Android 11+


  • Sort books by titleSort (title removing determiner: a, an, the).
  • Library switch in drawer sorted by title.


  • Android: improve compatibility with sdcard in recent Android versions.


  • Make slidable action in list view compatible with phone and tablet.


  • Remember last applied virtual view option for libraries, you can enable/disable that in settings.
  • Android: sort options for recently downloaded books list widget.
  • Android: Recently downloaded books stack widget.


  • Remember grid zoom level for libraries.


  • Disable default download path option in settings to avoid confusion.


  • Progress status bar for Smart Device book transfer.
  • Loading series and ratings information for Calibre-Web.


  • Mobile data saving mode, can be enabled/disabled in settings. Having saving mode enabled will only allow to download book cover and files when connecting to Wifi network.


  • Improve Calibre-Web support.
  • Double value support for series number.


  • Calibre-Web OPDS server support.
  • Better icon for custom columns in filter page.
  • Improve compatibility of custom column for content server.
  • iOS: improve user interface to avoid overlapping with bottom notch.


  • Android: home widgets for quickly access to recently downloaded books. You can update the widgets in the app from “All downloaded books” page or keep it update automatically in background every 30 minutes in settings page.
  • Android & iOS: improve user experience when syncing libraries. Improve integration with Calibre connection as Smart Device.


  • Mark books as read feature, swipe right from library view page for surprise.


  • Improve login experience for OneDrive and Box services


  • Release on iOS


  • Page for all downloaded books in cloud libraries.


  • Allow enabling back button to clear filters & virtual views
  • Library list view now shows series information.


  • Default value for boolean, rating, and languages in filters


  • Add Google Drive cloud service


  • Show book comment in book view page
  • Click to author show similar books
  • Improve sorting for large libraries


  • Send to Kindle


  • Save zoom level in grid view


  • Smart device - Calibre Wireless Device connection support


  • Improvement for virtual views, allow re-evaluating virtual views


  • Fix rating filter for Calibre Content Server


  • Support sort by custom columns


  • Add/remove selected books to/from virtual views
  • Batch download book with selected formats


  • Make sync library easier


  • Allow user to write note about books


  • Filter date columns by date range


  • Virtual views for libraries


  • Allow updating URL of Calibre Content Server


  • Introduce format V2 for libraries to provide better support for not clashing book with long name in same series.


  • Option to suppress errors downloading covers


  • Support for self-signed certificate servers


  • Add support for batch download and delete books


  • Allow one click to share with your favourite share app


  • Ability to download books to sdcard


  • Add PCloud EU region cloud service


  • NOT filter in filter page


  • Add support for Calibre Content Server
  • Book file formats can be opened in writable mode


  • Add support for WebDav servers


  • UI improvement, allow user to change primary color


  • Add Nextcloud and OwnCloud services


  • Make font size in book comment page resizable
  • Add AND filters on filter page
  • Add draggable scrollbar for library views (except carousel view)


  • Support for OneDrive share access


  • Stability improvement for Box cloud service


  • Support for local libraries on external storage


  • Support Android SDK 19 and 20 devices


  • Add OneDrive cloud service multiple accounts


  • Add pCloud cloud service


  • Add Box cloud service


  • Improve authentication for Dropbox


  • First release version