AlternativeTo Logo
calibre icon


E-book manager, viewer, and converter.

  • Mac
  • Windows
  • Linux
  • Homebrew
  • Flathub
  • BSD
  • Self-Hosted
Avg rating of 4.3 (30)| 32 comments

calibre Screenshots

Calibre collection on the iPhone
You can choose many languages
Cover Layout
Built-in Viewer
Another Cover Layout
 Suggest and vote on features

calibre Features

  1.  Built-in viewercalibre shows you a quick preview of an image, page or file in supported formats.
  2.  DRM FreeNo Digital rights management (DRM), i.e. no copy protection.
  3.  Portablecalibre can be used from a USB stick or similar with no prior installation.
  4.  Lightweightcalibre consumes less device resources compared to similar apps.
  5.  Extensible by Plugins/Extensionscalibre can be extended with add-ons, plugins and extensions.
  6.  Decentralizedcalibre is based on a decentralized infrastructure with no single entity controlling it.
  7.  Ebook ConversionConvert your ebooks to various formats (PDF, EPUB, MOBI…) and vice-versa with calibre.
  8.  Works Offlinecalibre can be used without the need to connect to the internet.
  9.  Handwritten Notescalibre supports writing by hand (or a stylus) and your text will be converted to text.

calibre information

  • Developed byKOVID GOYAL
  • LicensingOpen Source (GPL-3.0) and Free product.
  • Written in
  • RatingAverage rating of 4.3 (30 ratings)
  • Alternatives103 alternatives listed

Supported Languages

  • English

GitHub repository

  •  13,843 Stars
  •  1,822 Forks
  •  3 Open Issues
  •   Updated
View on GitHub

Popular alternatives

View all

Top calibre apps (extensions / mods etc)

View all

Our users have written 32 comments and reviews about calibre, and it has gotten 1260 likes

calibre was added to AlternativeTo by bak on and this page was last updated .

Comments and Reviews  Post a comment/review

 all • positive • negative      relevance • date
Top positive comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

Where are you getting ebooks that don't have ISBNs? Commercial ebooks do have ISBNs and Calibre does have the ability to extract those (or download from multiple online metadata sources) and list them in a column.

Calibre does copy all ebooks into a single directory PER LIBRARY. I have yet to determine the limit on how many libraries it will support, but I currently have separate library folders for Fanfiction, Short Unread Fanfiction, Long Unread Fanfiction, Unread In-Progress Fanfiction, Commercially Published Fiction, Cookbooks/Gardening, Manga/Graphic Novels, Nonfiction, Poetry, and a fileless database of my Physical Fiction collection (which I brought in as a list of ISBNs I scanned with a barcode reader into a file on my computer).

More than about 2000 books in a library does tend to slow it down, which is why I subdivided my libraries. A library with only metadata and no book files opens very fast.

Calibre does have an update notifier. When there's an update available, there will be a link at the bottom right. It does require you to download and install the update, but that's not really all that hard.

Calibre is primarily aimed at managing books, so all entries in the library are called "books" but the program will handle image, video, and audio files as well, and call your default program for that filetype when you click on it to open. Each "book" will accept multiple files, as long as there is only one of each format. For example, one book can have PDF, EPUB, MOBI, MP3, MP4, PNG, JPG, and ZIP, but you can't have a folder full of JPGs. Honestly, that's my main gripe. I prefer my graphic novels and downloaded webcomics as individually numbered image files, rather than forcing them into EPUB or ZIP.

There are lots of useful plugins, and if the default metadata options are insufficient, Custom Columns can be created. Too many Custom Columns may impact performance, depending on how many books Calibre has to sort when you use them, but you'd have to go pretty crazy with the columns.

There don't seem to be any AV-related metadata plugins yet. Someone requested an IMDB metadata plugin years ago, but since plugins are made by volunteers, there apparently hasn't been enough interest to get it done yet. Maybe someone could be persuaded to customize the Ant metadata scripts for Calibre...

Show entire comment
Top positive comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

Calibre is primarily a powerful ebook organizer and secondarily a viewer. For smaller epub and mobi files I find that Calibre works well enough even if the internal reader is simple. I suggest users setup Calibre to view PDF files in either Okular (linux) or SumatraPDF. The internal reader tends to be slow or occasionally crash with larger or unusual files regardless of ebook format.

You should take note of where Calibre is storing it's ebooks (Calibre Library icon > first line of text will contain your folder/path). From here add this path to a backup program so that you don't lose all the work you will eventually put into Calibre.

Calibre is incredibly good software and updated often. I have donated to the project twice and recommend others do so as well. $5 (or less) goes a long way towards helping the creators of open source software.

Show entire comment
Top negative comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

This software forces you to copy your entire ebook collection into a single directory. The developers aren't willing to consider anything else. Additionally, it doesn't modify the original files. So literally, this software will — without confirming with the user — duplicate your entire reading collection.

I've used the application for a number of years now and am abandoning it for good now. Can't believe this software won't let you manage a collection manually. I don't know about other users, but my reading collection contains both fiction and educational material, which I've spent a great deal of time organizing to be accessible. I'd love to use this application but it's just not possible unless you want to mix EVERYTHING you have into one folder. Yet another application that could be 100x better with little to no change but wont because the developers are religiously bound to a flawed approach to ebook management.

I recommend using another application called Blio for personal reading needs. It also has a flawed approach to file management, but it makes up for the fact with looks.

3 replies

I fully agree with you! I spent a lot of time to THINK about the best way to organize books even before using any e-book management software. I concluded that due to the following reasons:

  1. Lack of dedicated ISBN number filed in metadata in official standards for all the popular e-book file formats (PDF, CHM, DJVU, EPUB) I am forced to use file name as a ISBN storage. If popular e-book file formats did have dedicated ISBN number in that case ISBN number for my e-books would be inserted into book files (and then extracted easily with any e-book management software) and in that case I wouldn't care if Calibre or any other e-book management software insists on its own naming scheme. The essential point here is -> I cannot trust a buggy SW to control the connection between file names and ISBN numbers for my book collections!

  2. Performance hit when Calibre accepts a large number of new books (e.g. >100). Since Calibre insists on controlling book files it hits performance wall when it has to ask operating system's File System to check for name collisions for every file and directory created. I am using another e-book management software which does not care how the file will be named (in fact it relies on the fact that the book files already exist somewhere so there is no performance hit). Importing 500 book files in Calibre is extremely SLOW especially if your e-book collection is large. On the other hand importing 500 books in the SW I am using right now is almost instantly (however that SW is poor in search capabilities which is a strong feature of Calibre).

Normally I would use Calibre but due to its deep reliance on its file/folder naming control (which is deeply rooted in its architecture) I am forced to use a weaker SW... Too bad!

Reply written ago

If this reply contains spam or other abuse, notify admins about it.   

You just have to accept that the manager, manages your ebook collection for you. That's it. Simple!

Reply written ago

If this reply contains spam or other abuse, notify admins about it.   

I would not say Calibre is useless! It is the BEST ebook software out there. If you don't like it, you don't like any of them. You can always manage your ebooks manually however you like, but Calibre HAS to have its own libraries in order to store the metadata, sort books into folders, by author, etc. It's also very useful because you can search for a book by title or part of one, author, or part of an author's name, rating, etc. This would not be possible (or at best extremely slow) if you used your own folder system. It DOES sort all books into folders by author! They're readily accessible through your computer's File Manager, as well, if you want to find a book the hard way. I've done this using Thunar (which isn't available on Windows, for those of you thinking you could use a better file manager than the horrible one provided by MicroSoft.) AS to ISBN number, it CAN download that metadata from the web and insert it. It's not automatic because there are different sources, and you choose the best match. Otherwise you might get the WRONG metadata for a book titled "Ocean" By "Waves" or something. You can have multiple libraries. You can name them "Fiction" and "Education" and switch between them, in your example. If you do decide to modify the Calibre Libraries manually (say, adding a book, or modifying a book, or deleting a book) you will most likely ruin the databases for the metadata, number of books, etc. Instead, clone the library to another partition or drive and do your modifications there! Also, if you do manage the content of your Ebook reader manually you're doing it the slow, hard way, unless you have one with that capacity built in, such as Kindle (in which case, USE THE KINDLE software if you're happy with it.) On Android devices I sorely miss the full-blown Calibre. There are no good alternatives to it for this OS. They all require you to manually sort your book collection, which is difficult to even find in the Android file system and its persnickety icon based interface with all those slide and tap and touch the screen things (shudder)! I'd prefer an automatic Library where, when you open your Calibre application, you could sort your books, etc. as in the full Linux edition (and I suppose there's one for you few remaining Windows users, as well.) One day we'll have Android with NO ICONS and NO TOUCHSCREEN needed, I hope. Ubuntu almost had a solution... Calibre CAN modify original files, saving the originals. With this feature, you can convert books to other formats, MOBI to EPUB, etc, and you can optimize them for whichever reading device you prefer, Kindle, Nook, Kobo, etc. You can even modify an EPUB that has no chapter structure, and add a table of contents, if you want. You can edit a book with a lot of typos in it to correct them. As to others objections to its "clunky" look, YOU CAN MODIFY the interface however you like, removing icons/shortcuts you don't use, selecting wide or narrow screen format, etc. Yes, it CAN be slow if you try to add 100 books to an ereader device (also not recommended.) That's not Calibre, that's the DEVICE speed holding you back! If Calibre were slow in moving books, when you clone a library of 100 or even 500 books with it, it's almost instantaneous. I've done it. You COULD also do this using File Manager on your Linux based computer, of course. (I don't think you can do it with Windows, which is one of its many flaws.)

Reply written ago

If this reply contains spam or other abuse, notify admins about it.   
Show entire comment and 3 replies
Negative comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

A multifunctional program, even too much. I used it for a very long time until a very unpleasant situation when Calibre Viewer (viewer is for read) silently modified my EPUB files. The author of the program does not consider this a problem :-( So keep in mind.

Show entire comment
Positive comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

It's the best book reader available on the internet. If you don't want to use library to open your books you can change default epub application to "The calibre e-book viewer" which just opens book.

Show entire comment
Positive comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

It is the best ebook app. I expect it to grow and may be add AI features like DeepLearning and Natural Language Processing.

Show entire comment
Positive comment ago
Copy a direct link to this comment to your clipboard   
If this Review contains spam or other abuse, notify admins about it.   

users don't understand why calibre is making a copy of the files and stupidly getting angry but alright. It's simple because if the software tried to keep track of files all around the filesystem it would be a nightmare to try and keep track of them: user manually renaming the files, moving them, deleting, etc it would only remain the metadata but file would be gone. So Calibre was designed to prevent this kind of stuff and this way is better for synchronizing the library. Calibre is necessarily workarounding a filesystem issue. It's a simple concept to understand.

The biggest issue with Calibre is it's UX/UI.

Show entire comment
Show more comments
7 of 32 comments


  • Ebook Library
  • Ebook Reader
  • RSS to Kindle
  • bibliography-management
  • e-readers
  • bibliography
  • ebooks
  • ebook-management
  • e-book-readers
  • ereader
  • rating-system
  • EPUB
  • EPUB Reader
  • ebook-collection
  • Books
  • e-reader

Lists containing calibre

Literature •  eBOOK •  My Setup - All Apps and Software •  Reader

Recent user activities on calibre