CBconvert is a free, open-source tool that converts comic book files between CBR, CBZ, CB7, CBT, PDF, EPUB, and more. It offers powerful image processing, batch conversion, and works on Windows, macOS, and Linux.

🔍 What is CBconvert?

CBconvert is an open-source comic book file conversion tool capable of recognizing and converting common comic and document formats. Specifically, CBconvert supports CBR, CBZ, CB7, CBT, PDF, XPS, EPUB, MOBI, and even DOCX, PPTX, as well as plain folder contents. Users can leverage CBconvert to unify these formats into ZIP or TAR archive output.

Built with Go, this tool inherently carries excellent cross-platform genes, running smoothly on Windows, macOS, and Linux systems. Its emergence has dramatically simplified the process of managing and converting digital comics for enthusiasts.

✨ Core Feature Highlights

CBconvert is far more than a simple format converter — it is more like a Swiss Army knife for comic file processing.

🔄 Comprehensive Format Support

Wide input format support: Perfectly supports mainstream comic archive formats (CBR, CBZ, CB7, CBT), electronic documents (PDF, XPS), e-books (EPUB, MOBI), and even Office documents (DOCX, PPTX).

Streamlined output formats: Primarily converts to the highly universal CBZ (ZIP) or CBT (TAR) formats, ensuring smooth reading on any device or reader software.

🖼️ Powerful Image Processing Engine

This is one of CBconvert's killer features:

  • Format Conversion & Compression: During conversion, images can be unified into JPEG, PNG, WEBP, AVIF, JXL formats, with adjustable compression quality to effectively reduce file size.
  • Image Enhancement: Manually adjust image brightness and contrast to breathe new life into poorly scanned older comics.
  • Rotation & Grayscale: Supports image rotation (to fix scanning errors) and conversion to grayscale (to save space).
  • Precise Scaling: Scale images proportionally or to specified width/height, adapting to reading devices of different resolutions.

📑 Intelligent Content Management

  • Cover Extraction: One-click extraction of cover images from comic files, making it easy to create visual catalogs for your comic library.
  • Thumbnail Generation: Automatically generates smaller thumbnails for quick browsing and identification.
  • Batch Processing: Supports dragging multiple files or entire folders for conversion at once — highly efficient.

⚙️ Flexible Usage Modes

  • Clean Command-Line Interface (CLI): Provides precise control for advanced users and automation scripts.
  • Intuitive Graphical Interface (GUI): The Flatpak installation offers a graphical interface that is very user-friendly — just drag and drop to convert.

📊 How Does It Compare to Similar Tools?

The market has many format conversion tools, such as Calibre and various online converters, but CBconvert stands out particularly in the comic book vertical.

  • Feature/Tool: CBconvert | Calibre | Online Converter
  • Focus: Comics | General e-books | General files
  • Supported Comic Formats: Comprehensive | Average | Limited
  • Image Processing: Powerful | Basic | Very limited
  • Privacy: Local | Local | Files must be uploaded to server
  • Batch Efficiency: High | Medium | Low (usually queued)
  • Cross-Platform: Yes | Yes | Yes (via browser)

Summary of CBconvert's Unique Advantages:

  • Highly Specialized: Features are designed entirely around comic file processing and optimization, with no redundant functionality.
  • Privacy & Security: All conversion and processing is done locally on your computer, protecting your private comic collection.
  • Functional Depth: Provides professional image processing options such as brightness adjustment and AVIF/JXL new format support.
  • Open Source & Free: Completely free, community-driven, and continuously updated and improved.

🛠️ Usage Tips & Scenarios

Mastering some CBconvert usage tips can help it serve you better:

  • Device Compatibility First: When reading on different devices, prioritize formats supported by the device. CBZ (ZIP) is usually one of the best compatibility choices.
  • Batch Processing Saves Time: If you need to convert an entire comic library, be sure to use the batch processing feature to save significant time.
  • Image Adjustment Enhances Experience: For comics with poor scan quality, try fine-tuning brightness or contrast during conversion to improve reading experience.
  • Cover Extraction for Quick Browsing: The cover extraction feature helps you quickly browse and identify comic content, making collection organization easier.
  • Command-Line Automation: For tech enthusiasts, scripts can be written combined with the CLI to implement automated conversion workflows.

🚀 Efficient Usage Tips & Tricks

  • Batch Rename & Convert: If your comic library has messy naming, first use a file batch rename tool to organize them, then use CBconvert for unified format conversion — all in one go.
  • Optimize PDF Reading Experience: When converting scanned PDF comics, appropriately increase the --quality parameter and try fine-tuning --contrast to make text and lines clearer.
  • Optimize for E-readers: For a better reading experience on Kindle and other e-readers, output format can be CBZ, image format JPEG, and set --width 1200 (adjust according to your device's screen width) to effectively balance clarity and file size.
  • Create Personal Comic Summaries: Use --cover and --thumbs parameters to extract covers and thumbnails for your entire comic library, then use simple HTML or scripts to generate a visual index page — very intuitive for management.
  • Automated Workflow: If you're a tech enthusiast, you can integrate it into your own scripts to achieve a fully automated pipeline of "comic download → automatic conversion → sync to NAS/tablet."

📥 Download & Installation Guide

Installing CBconvert is very simple. Here are several mainstream installation methods.

Method 1: Install via Flatpak (First Choice for Linux Users)

  • This is currently the most recommended method, especially for Linux distributions. It manages dependencies conveniently and comprehensively.
  • Make sure your system has Flatpak support enabled.

Execute the following command in the terminal:

# Add Flathub repository (if not already added)
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
# Install CBconvert
flatpak install flathub com.github.gen2brain.cbconvert

After installation, you can find it in the application menu, or launch it via the terminal command flatpak run com.github.gen2brain.cbconvert.

Method 2: Download Pre-compiled Binaries Directly (Windows/macOS/Linux)

  • Developers publish pre-compiled programs for the latest versions on the GitHub Releases page, ready to use out of the box.
  • Visit CBconvert's GitHub Releases page.
  • Download the corresponding archive (usually .zip or .tar.gz format) based on your operating system (Windows, macOS, Linux).

Extract the downloaded archive.

  • (For Windows users) Simply double-click the extracted cbconvert.exe file to run it (command-line interface).
  • (For Linux/macOS users) Place the executable file in the system path (such as /usr/local/bin) or run it directly via the terminal ./cbconvert in its directory.

Method 3: Build from Source (For Developers or Enthusiasts)

Prerequisite: Go language environment (≥1.16) must be installed.

git clone https://github.com/gen2brain/cbconvert.git
cd cbconvert
go build -o cbconvert ./cmd/cbconvert

After successful compilation, an executable file named cbconvert will be generated in the current directory.

Basic Usage

After installation, you can use CBconvert via the command line:

# Basic conversion command
cbconvert input.cbr output.cbz

# Convert and adjust image quality
cbconvert input.pdf output.cbz --quality 85

# Convert and adjust image width
cbconvert input.cbr output.cbz --width 1200

# Batch convert entire folder
cbconvert ./input_folder/ ./output_folder/ --format cbz

Common Parameter Descriptions:

--format: Set output format (cbz, cbt, zip, tar)
--quality: Set image quality (1-100)
--width: Set image width (maintaining aspect ratio)
--height: Set image height (maintaining aspect ratio)
--brightness: Adjust brightness (-100 to 100)
--contrast: Adjust contrast (-100 to 100)
--cover: Extract cover image
--thumbs: Generate thumbnails

💎 Conclusion

CBconvert is a truly professional tool crafted for comic book enthusiasts, solving the pain point of multi-format compatibility. Whether it's simple format conversion or advanced image optimization, CBconvert handles it with ease. Its open-source nature means it will continue to evolve and keep pace with technological developments.

Most importantly, CBconvert gives you complete control over your comic collection, no longer constrained by specific devices or platforms. Start using CBconvert now and make your comic reading experience smoother and worry-free!

➡️ Visit CBconvert's GitHub project page now

Note: This is the English translation of the original Chinese version.