What's new
Key features
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Live previews for Text and Layout. The Text tab now shows a labelled preview at the text’s actual reading size. Layout shows the whole page while you adjust margins, so you can see the space around the text. Margin sliders have fewer drag stops, while the plus and minus buttons retain their finer adjustments.
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Collapsible chapter groups. Books with a nested table of contents can collapse and expand chapter groups. Choose Current section, All chapters or Off under Settings > Controls > Collapsible chapters.
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Custom hardware button actions. Assign Previous page, Next page or Do nothing to each available page button under Settings > Controls > Hardware buttons. Menus, lists and navigation previews retain their usual button directions. On Android, the same controls map the volume buttons.
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An optional standby override. Settings > System now offers Disable standby while reading. This may help with intermittent freezes or missed page turns on some Kobo devices, but it can significantly increase battery use and is generally not recommended. It is off by default, and you can still put the device to sleep manually.
Other additions
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Added About Kobalt, acknowledgments and license information to the Library’s More menu, available before opening a book.
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Enabled Kobalt sleep screens and native book covers in Tolino mode on supported firmware.
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Book-opening screens can reuse Kobo’s cached Library cover while a larger cover is being prepared.
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The final brightness or warmth percentage now stays visible for at least 1.5 seconds after a frontlight gesture.
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Link settings are grouped under a Links heading. The separate reading-page link indicator has been removed; tapping and long-press link actions remain available.
What's fixed
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Fixed the first KOSync upload on compatible servers that return a structured “not found” response for books without saved progress. Other errors still stop the upload, and progress conflicts still require a choice.
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KOSync now explains connection, certificate, authentication and server failures. Diagnostic logs record safe error categories without credentials or server response contents.
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Fixed long presses being interrupted by page-frame updates and accidentally turning the page.
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Fixed stale appearance previews after cancellation and reduced extra refreshes when opening or adjusting Layout.
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Header/footer customization now fits on one Clara-sized portrait screen at the normal interface text size.
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Made dialog headings, descriptions, dividers and option spacing more consistent.
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Fixed pinned bookmark shortcuts losing their opaque background after switching themes.
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Improved narrow Styling previews and made dictionary font-size labels fit the screen and interface text size.
Android
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Added volume-button mapping through Settings > Controls > Hardware buttons on devices with volume keys.
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Adjusted BOOX cleaning-refresh requests to use the device’s View API.
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Android remains experimental.
Installation on Kobo
The easiest method is Install or remove on Kobo in Chrome. For manual installation, download the package for your firmware:
- Kobalt-qt5.zip for firmware 4.38.21908 and later 4.x, tested up to 4.46.
- Kobalt-qt6.zip for firmware 5.18 and later 5.x, and 6.x.
Manual installation instructions
- Connect your Kobo over USB and extract the ZIP on your computer. Show hidden files to see
.addsand.kobo. - Copy the package’s
assetsfolder into.adds/kobalton the Kobo, replacing matching package files. Preserve your other files and folders. - Copy
KoboRoot.tgzfor Qt5, orKobo.tgzfor Qt6, into the Kobo’s.kobofolder. - Eject safely, disconnect USB and let the update install.
Copy the assets before the system package. Leave the .tgz compressed. Do not replace the entire .adds, .adds/kobalt or .kobo folder, as this can remove existing data or other mods.
Upgrading from beta 6
Upgrade over the existing installation; a clean install is not required. Close Kobalt and back up .adds/kobalt before updating. Keep that folder to retain your reading positions, book settings, bookmarks and annotations. The website is the easiest way to upgrade.
Beta 7 does not change the saved-data or database schema from beta 6. The new preferences use optional settings with defaults.
For installations still on older betas, legacy reading positions, book settings and bookmarks are imported into kobalt.sqlite. Migrated files are retained under migration-backup/. Keep your pre-upgrade backup if you need to return to an older release; the migration backup does not contain subsequent reading changes.
Installation on Android
Download Kobalt-android-arm64.apk and install it manually. Allow installation from the app opening the APK if Android asks. Android 9 or later on an ARM64 device is required.