What Is Calibre: Hands-on Review and Calibre DRM Removal Guide

When managing eBooks, I often run into problems like incompatible formats and strict protection that makes it hard to truly "own" the books I paid for. Calibre, as a free and popular eBook management software, finally lets me manage my entire library in one place and handle encrypted books flexibly.

Having used Calibre for over 12 years, I decided to write this Calibre review to explain what Calibre is, what it can do, and walk through its most popular function: eBook DRM removal. Based on my own experience, I'll also share my latest, efficient Calibre DRM removal workflow with BookFab.

Calibre Review: My Impressions of This Free eBook Tool

When I first started using Calibre, I just wanted a simple way to organize my scattered eBooks, but over time it became the "librarian" of my entire digital library. In this part, I'll explain what Calibre is, highlight its key features and safety, and then talk about my real experience plus other users' feedback.

What Is Calibre

Calibre is a free and open source e-book management software, created by developer Kovid Goyal in 2006. Over time, it has evolved into a cross-platform tool that supports Windows, macOS, and Linux, and can be seen as a complete e-book workstation. Its main function is to centralize e-books scattered across different folders and devices into a single virtual library. It can read most mainstream e-book formats, organize and edit metadata, convert between multiple formats, and sync in both directions with readers such as Kindle and Kobo.

Features of Calibre

1. eBook library management
Calibre can consolidate eBooks scattered across different folders and devices into a unified virtual library. You can filter and group by author, series, tags, ratings, and edit metadata or covers, making the collection clean and easy to search.

2. eBook format conversion
Calibre converts between major formats like EPUB, MOBI, AZW3, PDF, and TXT, with options to tweak fonts, spacing, margins, and table of contents for better reading on different devices.

3. Unlock ebooks via DeDRM plugin for Calibre
Calibre does not remove DRM on its own, but with third party plugins like DeDRM it can strip common DRM from Kindle, Adobe Digital Editions, Kobo, and more, so purchased eBooks can be read on more apps and devices.

4. Sync with Kindle, Kobo, and other readers
When a device like a Kindle or Kobo is connected, Calibre detects it, shows its books, and lets you send, delete, or auto convert files into device friendly formats for smooth syncing. It makes the whole Calibre send to Kindle workflow quick and easy.

5. Built-in reader and editor
Calibre includes a reader for formats such as EPUB and AZW3 with bookmarks and annotations, plus an "Edit book" module for deep editing of EPUB/AZW3 layout, HTML/CSS, chapters, and table of contents.

6. News fetching and magazine subscription
With preset or custom news sources, Calibre can regularly fetch content from websites and magazines and automatically package it into eBook format.

7. Calibre Content Server
Calibre's content server is used to publish the local library in a web based form, so that phones, tablets, or other computers can directly browse, read, and download eBooks through a browser. In practice, it functions like a personal eBook cloud server.

Is Calibre Safe

Is Calibre safe to download? Yes, Calibre is generally considered safe. It is an open source eBook management tool released under the GPLv3 license, with its source code fully public and continuously reviewed and maintained by the community. What really needs attention are the download source and version updates. The Calibre team recommends downloading the installer only from the official website and avoiding third party download sites that may offer tampered or ad bundled versions.

So, is Calibre safe to use? In terms of privacy, Calibre mainly runs locally. It does not force you to log into an account and does not sync your library to the cloud by default. Your book metadata, reading progress, tags, and other information are all stored in the local library, and whether to use cloud storage or the content server is entirely up to your own configuration.

Just a heads up: what you really need to pay attention to are third party plugins, especially the Calibre DeDRM plugin. These plugins usually come from GitHub or personal websites and are not officially maintained by the Calibre team, so you should always verify that the source is trustworthy and the version is up to date before installing.

Real Experience With Calibre

My Own Experience With Calibre

Calibre has made my eBook collection far more organized. It handles almost every format I own, lets me filter and edit metadata, and keeps my library neat and easy to search. With its conversion feature, I can switch between formats and tweak fonts and margins so books look good on my tablet, Kindle, or iPhone.

But I have to be honest: Calibre isn't perfect. As a free, open source tool, some things are still inconvenient. My most used feature, removing DRM, has become less reliable as Amazon updates its DRM, especially with newer Kindle KFX books. In some cases I still need an older Kindle for PC or extra plugins, which is annoying. This is why I've started pairing Calibre with BookFab for a smoother, simpler DRM removal workflow that I'll explain in detail later.

Feedback From Real Calibre 

I also collected feedback from long-time users on the official Calibre forum and the Reddit r/calibre community. Below is a summary of how users generally rate Calibre, which should help you see the tool more completely.

How to Use Calibre DeDRM Plugin to Remove DRM

One of Calibre's most used functions is to work with DeDRM plugins to remove DRM, and then convert ebooks to PDF or EPUB. In the following section, I'll show you detailed tutorials on how to remove Kindle, Kobo and Adobe DRM with this DeDRM plugin for Calibre.

Step 1: Download and Install Calibre

1. On the official Calibre download page, select the version that matches your operating system: Windows, macOS, or Linux.

2. After downloading Calibre, locate the downloaded installer file and double click it. Read and accept the license agreement, then click Install to start the installation. When the installation finishes, click Finish. Calibre will now be installed on your computer and ready for the next setup steps.

Step 2: Download and Install DeDRM Plugin for Calibre

1. Download the latest version of DeDRM Plugin here: DeDRM_tools_10.0.9.zip. 

2. Once you download DeDRM_tools.zip from GitHub, extract it to a local folder. You will see a file called DeDRM_plugin.zip. Do not unzip this file. This ZIP archive is the actual plugin used for DRM removal.

3. In Calibre, go to Preferences > Advanced > Plug-ins.

4. In the Plug-ins dialog, click Load plug-in from file….

5. In the file browser that appears, navigate to the folder where you extracted DeDRM_tools_10.0.9. Select DeDRM_plugin.zip (do not unzip this file) and confirm.

6. Calibre will display a warning about third-party plug-ins. Read it, then click Yes to continue and install the DeDRM plug-in.

7. After installation, a success notification will appear. Return to the Plug-ins list and expand File type plug-ins. You should now see DeDRM listed there. Once DeDRM appears under File type plug-ins, the plug-in has been successfully installed and Calibre is ready to remove DRM from supported eBooks.

Step 3: Remove DRM with Calibre

📱For Kindle:

1. Open the Kindle desktop app and download the Kindle eBooks you want to convert to a local folder.

2. In Calibre, click Add books to import your books. Alternatively, you can drag and drop the files directly from File Explorer into the Calibre window.

3. After Calibre finishes analyzing your books, select the eBook you want to convert and click Convert books in the toolbar.

4. In the Output format dropdown box, choose the format you want. You can also adjust advanced options, like editing the metadata.

5. Click OK and Calibre will remove the DRM and convert the eBook into the format you selected.

📱For Kobo:

1. Install the Obok Plugin on your PC. Restart Calibre, and you'll find Obok DeDRM has been activated and added in the top menu bar.

2. Download your Kobo books to your computer using Kobo for Mac or Kobo for PC. Launch Calibre and select Obok DeDRM from the top menu bar. A new window titled "untitled Obok DeDRM" will pop up, and all your downloaded Kobo books and their lock status will be displayed in detail. Click Select All, then click OK.

3. Calibre will begin the process of removing the DRM from your chosen Kobo books and will incorporate them into your Calibre library automatically. Once the process is finished, click OK.

📱For Adobe Digital Editions (ACSM Files):

1. In Adobe Digital Editions on your computer, download the book to your local drive. The default storage path is C:\Users\[Username]\Documents\My Digital Editions. (On macOS: Documents/My Digital Editions.)

2. Click the Add Books. Browse to the My Digital Editions folder and select the EPUB/PDF files you want to import into Calibre.

3. After Calibre finishes adding and analyzing the books, select a title and click Convert books in the toolbar.

4. In the Output format drop-down list, choose the format you want to create. Click OK to start the conversion. In the conversion, Adobe DRM will be removed simultaneously.

Common Calibre DRM Removal Issues and How to Fix Them

DeDRM plugin for Calibre is an unofficial file. While it can remove eBook DRM to some extent, it does have some drawbacks. As a result, there are situations where Calibre still cannot decrypt an eBook even if you have the plugin installed. Below are some commonly reported errors and their corresponding solutions.

From the points above, it's clear that Calibre DeDRM plugin has some inescapable limitations:

• The newer Kindle KFX format cannot be handled directly by Calibre.
• Its compatibility is very fragile and can easily break when Calibre updates.
• The installation and configuration process is complicated.
• Its stability and maintenance cannot be guaranteed.
• It cannot handle books borrowed from services like Kindle Unlimited.

So, although Calibre dominates the eBook management space and is arguably the best "librarian," it is not the best "locksmith." Does this mean eBook decryption and management is an unsolvable problem? Not at all. Next, I'll show you a smoother, simpler, and far more powerful decryption workflow by using Calibre's best companion, Bookfab, to upgrade your eBook decryption experience.

Best Companion to Calibre: BookFab 

BookFab is an eBook decryption and conversion toolkit for Kindle and Kobo users. It includes Kindle Converter and Kobo Converter, which can remove DRM from supported titles and convert them to the widely compatible EPUB format with batch processing while preserving key metadata.

Besides the standalone app, BookFab also provides a Calibre DRM removal plugin. After installing the plugin to Calibre, you can call BookFab's decryption engine directly inside Calibre to remove DRM from the latest Kindle books, with support for all Kindle formats and without dealing with Calibre DeDRM or KFX plugins. The decrypted books are then imported into Calibre automatically for seamless ebook management.

Use Case 1: Using BookFab Calibre Plugin

This method is ideal for users who are already used to managing their library with Calibre. You can trigger BookFab's decryption capabilities directly from within Calibre, and once the process is complete, the DRM-free Kindle books are automatically written back to the same Calibre entry. 

Step 1: Install BookFab Software 

Since the BookFab Calibre plug-in relies on the decryption capabilities of the BookFab desktop client, you need to download and install the BookFab desktop app first. For the best compatibility, make sure your BookFab desktop client is updated to the latest version.

After the installation is complete, log in to your BookFab account.

Step 2: Install BookFab Calibre plugin

Click and download BookFab Calibre plugin here: Bookfab_Calibre_Plugin_v1.0.0_40db112e.zip.

In Calibre, go to Preferences > Plugins > Load plugin from file, then select the downloaded BookFab Calibre plugin file and add it to Calibre.

After completing the installation with the wizard, restart Calibre. You will see the BookFab Remove DRM plugin icon in the top menu bar of Calibre.

Step 3: Add eBooks

Use Kindle for PC to download the Kindle eBooks you want to process to your computer.

In Calibre, click Add books and import these books into your library.

Step 4 Start decryption via BookFab

In the Calibre library list, right-click the Kindle book you want to strip DRM from and choose Remove DRM. Confirm to start the process. After decryption finishes, the DRM-free version of the eBook is automatically written back to Calibre.

Use Case 2: Using BookFab as a Standalone Converter

For customers who want the easiest technique and don't want to deal with Calibre plug-ins, this approach is perfect. Here is the tutorial on Kindle DRM removal with BookFab Kindle Converter.

Step 1: Download and install BookFab Software

Step 2: Open BookFab Kindle Converter and add your books

Use the Kindle for PC desktop app to download the Kindle eBooks you want to process to your computer.

Open BookFab and select the Kindle Converter module from the sidebar. In the Import Kindle Files section, click Select Files, and load the downloaded eBooks into the software.

Step 3: Download the DRM-Free Kindle Book

After the upload is complete, BookFab will display a list of your Kindle books. Check the titles you want to process, then click Decrypt & Convert. The files will be immediately analyzed and decrypted. Once the decryption is finished, the status in the left-hand list will be updated. In the Download List, click the folder icon to open the output folder where your DRM-free Kindle books are saved.

Conclusion 

Calibre is a powerful, free, and safe eBook management tool. With the help of the third party DeDRM plugin for Calibre, it can remove DRM from eBooks. However, the plugin is hard to set up, has poor compatibility, and does not support the latest Kindle DRM. That's why I recommend using the BookFab Calibre plugin instead: let Calibre handle library management and let BookFab handle decryption, so you can enjoy the smoothest eBook workflow Calibre has ever had.