Library File Structure

How you organize files on disk determines what BookOrbit imports. This page covers the recommended layouts for every library type, what sidecar files are recognized, and how to handle real-world collections.

The golden rule

Every library has a scan mode chosen during setup. That mode must match how your files are laid out on disk - everything else follows from it.

Scan mode	What it creates	Use when
Folder as Book	One book per folder. All files inside are grouped together.	Almost always. Required for audiobooks, multi-format books, and any library with cover or OPF sidecar files.
File as Book	One book per file. Folder structure is ignored.	Only for a flat ebook dump with no sidecar files and no multi-format grouping needed.

Tip

For ebooks and comics, Folder as Book is always the safe default - files with different names in the same folder are imported as separate books.

For audiobooks, Folder as Book requires that each audiobook has its own dedicated folder. If any subfolder contains audio files, BookOrbit treats that entire folder as one audiobook - all tracks merged together, regardless of their names. See the Audiobooks section below.

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Ebooks

Use Folder as Book with one subfolder per book. Inside each folder, put the book file, an optional cover image, and an optional OPF metadata sidecar.

Ebooks/
  Dune/
    Dune.epub
    cover.jpg
    Dune.opf
  Project Hail Mary/
    Project Hail Mary.epub
    cover.jpg

If you have the same book in multiple formats, put them all in the same folder. BookOrbit groups them into one book and uses the library’s Format priority to decide which is primary. You can read in any available format from the book detail view.

Ebooks/
  The Hobbit/
    The Hobbit.epub
    The Hobbit.mobi
    The Hobbit.pdf
    cover.jpg

Flat ebook collections (File as Book)

If your entire collection is a single folder of files with no subfolders and no sidecar files, use File as Book mode instead. No subfolders needed.

Ebooks/
  Dune.epub
  Foundation.epub
  The Hobbit.mobi

Caution

In File as Book mode, cover images and OPF metadata files are never associated with a book - each file is completely standalone. If you ever want to add sidecar covers or have multiple formats per book, switch to Folder as Book before your collection grows.

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Audiobooks

Always use Folder as Book for audiobooks. File as Book cannot group multiple tracks into one book and will not correctly import multi-disc libraries.

Caution

Each audiobook must have its own dedicated folder. The moment any subfolder contains an audio file, BookOrbit treats that entire folder as one audiobook - all audio files merged together, no matter their names. Never put multiple unrelated audio titles in the same subfolder.

Single-file audiobook

One audio file in its own folder.

Audiobooks/
  Project Hail Mary/
    Project Hail Mary.m4b
    cover.jpg
  The Martian/
    The Martian.mp3
    cover.jpg

Multi-track audiobook

Multiple audio files in one folder are automatically grouped into one book. Files are sorted by filename for playback, so use zero-padded numbers to get the right order.

Audiobooks/
  Dune/
    01 - Dune.mp3
    02 - Dune.mp3
    03 - Dune.mp3
    cover.jpg

Tip

Always zero-pad track numbers: 01, 02 ... 09, 10, 11 not 1, 2 ... 9, 10, 11. Without padding, 10 sorts before 2 alphabetically, which breaks playback order.

Multi-disc audiobook

Put disc tracks in subfolders named with a recognized disc pattern. BookOrbit flattens them into the parent book automatically - no extra configuration needed.

Audiobooks/
  The Way of Kings/
    Disc 1/
      01 - Track.mp3
      02 - Track.mp3
    Disc 2/
      01 - Track.mp3
      02 - Track.mp3
    cover.jpg

Recognized disc folder names (case-insensitive): CD 1, Disc 2, Disk 3, Part A, Side IV. The number can be a digit, letter, or roman numeral.

Caution

Only these specific patterns are treated as disc folders. Names like Volume 1, Book 1, or Part One (spelled out) are not recognized and will be imported as separate books instead of disc groupings. Rename them to Part 1, Disc 1, etc.

Audiobook with companion ebook

If you have both an audio file and an ebook for the same title, use a subfolder named exactly after the audio file’s stem. BookOrbit absorbs the subfolder into the parent book.

Audiobooks/
  Dune/
    Dune.m4b
    Dune/            ← same name as the .m4b stem - gets absorbed
      Dune.epub
    cover.jpg

Both files become part of the same book record.

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Comics

Use Folder as Book. One folder per title or issue.

Single-volume or graphic novel

Comics/
  Watchmen/
    Watchmen.cbz
    cover.jpg
  Batman - Year One/
    Batman - Year One.cbr
    cover.jpg

Multi-issue series

Give each issue its own folder so they appear as individual books in the library. Use zero-padded issue numbers in folder and file names to keep them in order.

Comics/
  The Sandman/
    The Sandman 001/
      The Sandman 001.cbz
    The Sandman 002/
      The Sandman 002.cbz
    The Sandman 003/
      The Sandman 003.cbz

Tip

If you want the whole series as one browseable run, use BookOrbit’s Series field and series index rather than trying to group issues into one folder. The series view collapses them into one entry in the grid automatically.

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Sidecar files

Sidecar files live in the same folder as the book and are associated with it automatically. They do not become separate book records.

Cover images

The file extension can be jpg, jpeg, png, webp, gif, or bmp. The filename (without extension) must be one of:

Filename	Notes
cover	Recommended - most universally recognized
folder	Common in audiobook rips
thumbnail
artwork
front

Any other image in the folder - back-cover.jpg, author.png, map.webp - is ignored.

Metadata sidecar files

Files with extension .opf or .nfo in the same folder are read as metadata sidecars. Whether they take precedence over embedded metadata depends on the library’s Source precedence order, set on the Metadata step during library creation.

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Grouping folders

Your library folders can have intermediate grouping folders - for example, sorting books by author or genre. BookOrbit walks the entire folder tree and handles them correctly, as long as each actual book lives in its own leaf folder.

Ebooks/
  Sci-Fi/               ← grouping folder, not a book
    Isaac Asimov/       ← grouping folder, not a book
      Foundation/
        Foundation.epub
      I Robot/
        I Robot.epub
  Fantasy/
    Dune/
      Dune.epub

Tip

Deep nesting works, but it adds maintenance overhead that BookOrbit’s built-in tools make unnecessary. Collections and Smart Scopes let you group, filter, and browse by genre, author, or series without touching the folder structure at all. A flat two-level layout (Library root > Book folder) is the easiest to maintain long-term.

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Exclude patterns

If your library folder contains non-book directories or files you want the scanner to ignore, add exclude patterns on the library’s Scanner step. Patterns are matched against the file or folder name only - not the full path.

Pattern	What it skips
samples	Any file or folder named exactly samples
*.tmp	Any file ending in .tmp
*_sample.*	Files like Dune_sample.epub
extras	A folder named extras

Tip

Use literal names for folders and simple * wildcards for file patterns. Full-path patterns like **/samples are not supported - only the entry name is matched.

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Tips and tricks

Set your scan mode before importing. Changing from File as Book to Folder as Book (or vice versa) after books are already imported forces a full rescan and can change which files are treated as books vs sidecars. Choose the right mode during library creation.

Multiple formats in one folder are always better than separate libraries. If you have both EPUB and MOBI versions of a book, keep them in the same folder. BookOrbit shows them as one book with multiple available formats.

Keep the Book Dock folder separate from your library folders. The Book Dock staging folder is managed internally by BookOrbit. Adding it as a library folder will cause duplicate imports.

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Troubleshooting

A multi-file audiobook was split into separate books

1. Check the scan mode. File as Book creates one record per file by design. Switch to Folder as Book under Settings > Libraries > Edit > Scanner and re-scan.
2. Check that all tracks are in the same folder. Each subfolder becomes its own book unless it has a recognized disc name.
3. Check disc subfolder names. Only CD N, Disc N, Disk N, Part N, and Side N are flattened. Volume 1, Book 1, and spelled-out names like Part One are treated as separate books - rename them and re-scan.

A sidecar cover or OPF is not being picked up

• Confirm the cover filename is exactly one of: cover, folder, thumbnail, artwork, or front (with an image extension). Other image filenames are ignored.
• Confirm the sidecar is in the same folder as the book file, not a parent or sibling folder.
• If you added the sidecar after the initial import, run a manual Scan - the watcher may not trigger a full folder re-import for sidecar-only changes.

Disc folders are creating separate books instead of one audiobook

The subfolder name does not match the disc pattern. Rename it to Disc 1, CD 1, or Part 1 (numeral required - Part One does not match) and run a manual Scan.

A book appears twice

Two different folder paths are being treated as separate books. This usually happens when a file exists both at the library root and inside a subfolder. Remove the duplicate file and re-scan.