3DSlibris

3DSlibris
General
Author	Rigle
Type	Utilities
Version	1.0.3
License	GPL-2.0
Last Updated	2026/03/14
Links
Download
Website
Source

Nintendo 3DS homebrew ebook reader based on the original Nintendo DS project dslibris.

3dslibris ports the original architecture to libctru, keeps the fast text-first reading model, and adds practical 3DS UX improvements (grid library, cover thumbs, indexed navigation, procedural UI skin, orientation-aware touch, etc.).

The current .cia packaging flow is based on the same makerom/bannertool process used by Universal-Updater, adapted to this project's assets and release layout.

Features

• Custom fonts.
• Bookmarks.
• Table of contents/index support.
• Left- and right-handed layouts.
• Three color modes: Daylight, Night, and Book.
• Strong EPUB support.
• Good FB2, TXT, RTF and ODT support.
• Experimental MOBI support.

Installation

Recommended install:

• Download 3dslibris-sdmc.zip from GitHub Releases.
• Extract that zip into the root of your SD card, so it expands into sdmc:/.
• Put your books in sdmc:/3ds/3dslibris/book/.
• Launch sdmc:/3ds/3dslibris/3dslibris.3dsx from Homebrew Launcher.

Alternative install:

• Install 3dslibris.cia.
• Keep the same runtime folders on SD, including sdmc:/3ds/3dslibris/font/ and sdmc:/3ds/3dslibris/resources/.
• Put your books in sdmc:/3ds/3dslibris/book/.

Important:

• Keep the packaged font/ and resources/ folders exactly inside sdmc:/3ds/3dslibris/.
• If those runtime files are missing, 3dslibris now stops at boot and tells you to reinstall 3dslibris-sdmc.zip.
• 3dslibris-debug.3dsx uses the same SD layout and writes verbose diagnostics to sdmc:/3ds/3dslibris/3dslibris.log.
• The .cia build uses the Universal-Updater-style packaging flow, but the runtime SD layout is the same as the .3dsx install.

Generated install package targets:

• make package-sdmc stages dist/sdmc/... with 3dslibris.3dsx included
• make zip-sdmc creates dist/3dslibris-sdmc.zip
• make cia creates 3dslibris.cia
• GitHub Releases: pushing a tag like v1.0.3 triggers .github/workflows/release.yml and attaches 3dslibris.cia, 3dslibris.3dsx, 3dslibris-debug.3dsx, and dist/3dslibris-sdmc.zip to the release

Bundled runtime files:

• sdmc/3ds/3dslibris/resources/splash.jpg
• sdmc/3ds/3dslibris/resources/ui/icons/png/*.png
• sdmc/3ds/3dslibris/book/README.md
• sdmc/3ds/3dslibris/font/README.md
• sdmc/3ds/3dslibris/font/Liberation*.ttf
• sdmc/3ds/3dslibris/font/OFL-1.1.txt

Notes:

• Homebrew Launcher path: keep the app at sdmc:/3ds/3dslibris/3dslibris.3dsx
• Debug build path: keep 3dslibris-debug.3dsx in the same sdmc:/3ds/3dslibris/ folder if you want verbose logs
• Default Liberation fonts are bundled in sdmc:/3ds/3dslibris/font/
• You can replace them with other .ttf, .otf, or .ttc fonts if you want to customize the reading/UI typefaces
• Runtime files such as 3dslibris.xml, 3dslibris.log, and cache/* are created by the app on first run

sdmc:/3ds/3dslibris/3dslibris.3dsx
sdmc:/3ds/3dslibris/book/*.epub|*.fb2|*.txt|*.rtf|*.odt|*.mobi
sdmc:/3ds/3dslibris/font/*.ttf
sdmc:/3ds/3dslibris/resources/splash.jpg
sdmc:/3ds/3dslibris/resources/ui/icons/png/{back,gear,home,next,prev}.png

Supported formats

Strong support

• EPUB (EPUB2 + EPUB3 NAV/NCX parsing with robust fallbacks)

Good support (text-oriented)

• FB2
• TXT
• RTF
• ODT

Experimental / best-effort

• MOBI
  • First open can be slow on large books (decompress + parse + pagination)
  • Subsequent opens are accelerated by persistent page cache
  • TOC quality is heuristic for many files (can be approximate)
  • Includes an optional per-book line wrap fix for badly converted files that hard-wrap prose line by line
  • Empty or corrupt books are reported with a readable error instead of a raw numeric code

Known limitations

• Some EPUB files have malformed anchors; index jumps can be approximate when source metadata is broken.
• MOBI TOC extraction depends on file structure and may omit or merge entries in some books.
• Some malformed MOBI sources still contain encoding or OCR artifacts that cannot be repaired reliably on the reader side.
• After changing font size, paragraph spacing, orientation, reading fonts, or the per-book MOBI line wrap fix, reopen the current book to apply the new layout.
• Reading position and existing bookmarks are remapped approximately after that reopen and can shift a few pages from their original location.
• No DRM support.

Controls

A/B/L/R - Turn pages

D-Pad Left/Right - Jump between bookmarks

Y - Toggle bookmark

X - Change background color

Select - Settings

Start - Return to library

Touch UI for library, settings, index, bookmarks, font menus...

Screenshots

Known issues

https://github.com/RigleGit/3dslibris/issues

Changelog

v1.0.3

• Highlights
  • Pressing right on settings rows such as font size and paragraph spacing now increases the value.
  • Pressing left now decreases the value, matching the on-screen arrows and touch layout.
  • Horizontal navigation inside the settings list is aligned with the same left/right direction.
  • The main browser splash now shows the app version centered at the bottom of the left screen.
  • Changing font size, paragraph spacing, orientation, or reading fonts no longer tries to repaginate the book inside the settings menu.
  • When layout-related settings change, the app shows a warning and applies the new layout after reopening the current book.
  • MOBI parsing is more resilient against empty or corrupt files and now shows a readable error instead of a raw numeric failure.
  • MOBI books now have an optional per-book line wrap fix for badly converted files that hard-wrap normal prose into many short blocks.
  • The .cia packaging flow was rebuilt around the same makerom/bannertool process used by Universal-Updater.
  • Previous 1.0.3 test .cia builds could install but fail to boot because the packaged exheader ended up with an invalid main-thread priority.
  • The generated .cia now boots correctly on original hardware and in Azahar.
• Known bug
  • When a book is reopened after a layout change, or after toggling the per-book MOBI line wrap fix, reading position and existing bookmarks are remapped approximately and may land a few pages away from their original location.
  • Some malformed MOBI files still contain source encoding or OCR artifacts that cannot be repaired fully by the reader.

v1.0.2

• Highlights
  • Startup now stops with clear install guidance if required runtime files are missing from the SD card.
  • The error message tells users to download and extract 3dslibris-sdmc.zip and shows the expected sdmc:/3ds/3dslibris/ layout.
  • The README now explains installation step by step for the .3dsx + SD package flow.

v1.0.1

• Highlights
  • EPUB cold opens are now much faster on large books by indexing ZIP entries before spine parsing.
  • In real tests with Don Quijote, cold open time dropped from about 50.5s to about 7.2s, roughly a 7x improvement.
  • Releases now include 3dslibris-debug.3dsx, which enables verbose diagnostic logging in 3dslibris.log.
• Notes
  • The debug build is intended for troubleshooting and performance investigation.
  • EPUB TOC resolution remains separate from the main open path and was not the main cause of the previous cold-open slowdown.

v1.0.0

• First release.

Credits

• Original dslibris: Ray Haleblian
• 3DS port and maintenance: Rigle

External links

• GitHub - https://github.com/RigleGit/3dslibris
• GBAtemp - https://gbatemp.net/threads/release-ebook-reader-for-nintendo-3ds-3dslibris-dslibris-port.680297/