18 august 2025 Release
Ubooquity 3.1.0 is available, this is the first stable version of Ubooquity v3 !
Download Ubooquity
The most important features (Java 17 requirement, theme system, database changes, reading progress...) have been part of version 3.0.0, so you can find related information in the version 3.0.0 BETA announcement post.
Here is what changed since version 3.0.0.
Features
- made duplicate logging optional (as it is very CPU intensive)
- added optional auto database backup upon collection scan
To activate this automatic backup, add the "databaseBackupFolder" parameter in your preference file (preferences-2.json
), after having stopped your Ubooquity instance.
Example: "databaseBackupFolder" : "D:/Tom/ub-backup-folder"
Each time a scan is launched, Ubooquity will backup the database file, creating the file ubooquity-db-backup-1.zip
. If the backup file already exists when the scan is launched, it is first renamed to ubooquity-db-backup-2.zip
, so you have the last two version of your database backed up.
Bug fixes and improvements
- fixed sorting issue
- fixed OPDS issue
- fixed page reader bug that prevented closing when reading book from the 'latest' section
- fixed JBig2 issue and upgraded PDFBox to version 3
- improved session cookie security
- fixed wrong parent URL in library
- fixed a bug preventing the sharing of folder having similar partial names
- fixed wrong publication date field taken from ComicInfo.xml (needs a database rebuild for the data to be fixed)
- fixed cbz files downloaded as cbz.zip files on Android
13 october 2024 Release
A new minor version of Ubooquity v2 was published to further improve the security of cookies for user and admin sessions.
It is available on the download page.
15 september 2024 General, Release

I have been informed today of a severe vulnerability in the last available version of Ubooquity 2 (version 2.1.2).
A fixed version is available on the usual download page, version 2.1.4.
Please update as soon as possible.
Ubooquity 3 is not impacted by this vulnerability and can be used safely.
15 october 2023 General
A BETA version of Ubooquity 3 is available.

Due to the high number of changes made since the last release, a few bugs might still be around.
Wait a few weeks for the next stable release(version 3.1) if you want to minimize the risk of issues.
Until that stable release is available, the download and documentation pages of this site will still reference Ubooquity 2.
Documentation specific to version 3 is mentionned below.
New requirements and migration from version 2
The minimum Java version required to run Ubooquity is now Java 17.
When coming from Ubooquity version 2, your preferences (in the preferences.json
file) will be automatically converted to the new preference format (in the preferences-2.json
file) without erasing them. The whole database will have to be recreated though, meaning your collection will have to be rescanned.
Themes from version 2 are not compatible with version 3, you should revert to the default theme (in the settings) if you use a custom theme.
Download Ubooquity 3 BETA
New features
- Comics and books sections have ben unified. When sharing a folder, you have to select a category (comics, books, magazines, documents or others), but this category will just be used to group the files on the home page, Ubooquity no longer treats your files differently depending on their section/category.
- Reading progress is now displayed in the library and details views, with "mark as read/unread" buttons in the details.

- Themes have been made much more flexible, with full control over the HTML files. See the dedicated documentation for more details, and the variable reference for a complete list of the data you can use in your custom themes:
- Thumbnail compression level can now be adjusted in the settings.
- Two new API endpoints (callable using a secret API key, see the advanced settings page for details and examples) were added:
- one to remotely trigger a collection scan
- one to remotely trigger a server shutdown.
- Duplicate files detection: at the end of each scan Ubooquity will list in the logs the duplicates it found (files with the same name and size).
Other changes
- Fixed display of transparent images in DJVU documents.
- Upgraded all dependencies.
- Made epub parsing more resilient.
- Improved handling of files with incorrect extensions.
- Reimplemented the desktop UI in Swing since Java 11+ does not support JavaFX out of the box anymore.
- Ubooquity is now developped in Kotlin, although a lot of Java code is still there. Full code conversion/rewrite will be done progressively.
- A lot of miscellaneous small bug fixes.
13 december 2021 General
You might have heard about Log4shell, a critical vulnerability in the widely used Log4j logging library.
Ubooquity does not use this library (logging is done with Logback), so it is not affected by this vulnerability.