Calibre is a powerful ebook management tool. It rigidly enforces Author/Title/ folders, though. Libiry can work with that folder structure as well, but does not enforce it.

Because Libiry allows you to store your books any way you want, the

When you maintain book metadata, you must either do that in Calibre or in Libiry. Because Libiry allows you to have your own folder structure, Calibre’s OPF solution will not work. or your metadata however, but has a different way of editing metadata when you want to edit tags and other book metadata, complements Calibre by providing:

  • Visual grid-based browsing
  • Quick tag filtering and editing
  • Physical book cataloging
  • Mobile-friendly interface

Typical workflow:

  • Use Libiry for visual browsing, searching, metadata management, and as a starting point to read
  • Use Calibre to read individual books, track your progress in these books and convert them to other formats

Setup

Optional: convert some book formats to streamline your book collection first

Libraries can get messy when they contain lots of small files. If you like to use your own folder structure but would like to limit the number of OPF files, consider converting your CBR files to CBZ files and your MOBI, AZW and AZW3 files to EPUB files. You can do that in Calibre. It will eliminate the need for separate OPF files for these books. You can

Point Libiry to your Calibre Library

  1. Open Libiry Settings
  2. Set the Location to your Calibre library folder
    • Default Windows: C:\Users\<user>\Calibre Library
    • Default macOS: ~/Calibre Library
    • Default Linux: ~/Calibre Library
  3. Save settings

Calibre library structure

Calibre organizes books by author:

Calibre Library  
├── Margaret Atwood  
│ ├── The Handmaid's Tale (1)  
│ │ ├── The Handmaid's Tale - Margaret Atwood.epub  
│ │ ├── cover.jpg  
│ │ └── metadata.opf  
│ └── The Testaments (2)  
│ └── ...
├── William Gibson  
│ └── Neuromancer (3)  
│ └── ...
└── metadata.db

Libiry allows any given folder structure. It reads all folder reads:

  • Ebook files (EPUB, MOBI, PDF, etc.)
  • Cover images (cover.jpg)
  • Metadata from ebook files

With the tool Calibre2Libiry you can rename all of Calibre’s opf files and image files from

  • metadata.opf → book.pdf.opf
  • cover.jpg → book.pdf.jpg
  • cover.png → book.pdf.png

After that, you can change your folder structure any way you want.

Metadata compatibility

What Libiry reads from Calibre books

Calibre fieldLibiry fieldNotes
titlebooktitleFull support
authorsauthorFull support
tagstagsPartial support
ratingratingCalibre: 0-10, displayed as 0-5 stars
ISBNisbnFull support
publisherpublisherFull support
publishedyearYear extracted
commentsdescriptionFull support
seriesseriesFull support
series indexseries_indexFull support
opf:file-as attribute op dc:creatorauthor_sortFull support
dc:contributor with opf:role=“trl”translatorFull support
dc:contributor with opf:role=“ill”illustratorFull support
complete dc:date (YYYY-MM-DD)publication_dateFull support
Calibre metadata or rendition:page-countpagesFull support
languagelanguageFull support

Tag synchronization

EPUB files: Tags sync both ways

  • Edit in Calibre → visible in Libiry
  • Edit in Libiry → visible in Calibre (after refresh)

Other formats: May require OPF files

PDF tags

Calibre stores PDF tags differently:

  • Calibre uses metadata.opf in the book folder
  • Libiry uses the PDF keywords field or an OPF file

For best compatibility, use Libiry’s OPF files for PDFs.

Calibre plugins

Enhanced metadata

If you use Calibre plugins for metadata:

  • Metadata stored in ebooks propagates to Libiry
  • Custom columns don’t sync (Calibre-specific)
  • Standard fields work everywhere

Reading progress

Calibre’s reading progress doesn’t sync to Libiry. Consider using tags like reading, read, to-read.

Calibre custom columns

Calibre custom columns (column) are stored in metadata.db, not in ebook files. These don’t appear in Libiry. Consider using tags instead of custom columns for data that should be visible in Libiry.

Cover images

Calibre generates covers at specific sizes. Libiry extracts covers independently, so covers may look slightly different. Both are correct; Libiry just re-extracts.

OPF metadata files

Calibre creates metadata.opf files in book folders. These are Calibre-specific and different from Libiry’s OPF metadata files.

Avoiding conflicts

File locking

Don’t edit the same book in both tools simultaneously. Make changes in one tool. Close/refresh before using the other.

Database integrity

Libiry never modifies Calibre’s metadata.db.