CBR to CBZ Converter

A command-line tool to convert .cbr (Comic Book RAR) files to .cbz (Comic Book ZIP) files with maximum compression.

Features

• Batch Processing - Processes a batch of files in a directory automatically
• Maximum Compression - Uses the max compression rate for zips automatically
• Progress Tracking - Shows conversion progress and file size comparisons
• Smart Skipping - Avoids overwriting existing CBZ files
• Optional Cleanup - Prompts to delete original CBR files after conversion

Download

Download the latest release for your platform from the releases page. I have only personally tested the Windows .exe file, but all the other should work in theory. Supported platforms are Windows, MacOS, Linux (amd64, arm64)

Quick Start

Windows

1. Download cbr2cbz.exe from releases or compile it yourself
2. Place it in the folder containing your .cbr files
3. Double-click cbr2cbz.exe or run it from Command Prompt
4. Follow the prompts

Linux/macOS

1. Download the binary from releases or compile it yourself
2. Make it executable: chmod +x cbr2cbz-linux # or cbr2cbz-macos
3. Place it in the folder with your .cbr files
4. Run it: ./cbr2cbz-linux # or ./cbr2cbz-macos

Usage

Simply place the executable in a directory containing .cbr files and run it:

cbr2cbz.exe  # Windows
./cbr2cbz    # Linux/macOS

The tool will:

1. Scan the current directory for all .cbr files
2. Convert each file to .cbz format with maximum compression
3. Display progress and file size comparisons
4. Provide a summary of successful/failed conversions
5. Ask if you want to delete the original .cbr files

Example Output

CBR to CBZ Converter
============================================================
Found 3 CBR file(s) to convert
============================================================

Processing: Amazing Spider-Man 001.cbr
  → Extracting...
  → Creating CBZ with 24 files...
  ✓ Created: Amazing Spider-Man 001.cbz
    Original: 45.32 MB
    New: 42.18 MB
    Change: -6.9%

Processing: Batman 001.cbr
  → Extracting...
  → Creating CBZ with 28 files...
  ✓ Created: Batman 001.cbz
    Original: 52.14 MB
    New: 48.92 MB
    Change: -6.2%

============================================================
Conversion Summary:
  ✓ Successful: 2
  ⚠ Skipped: 0
  ✗ Failed: 0
  Total: 2

============================================================
Delete original .cbr files? (yes/no):

Building from Source

Prerequisites

• Go 1.16 or later

Build Instructions

1. Clone the repository:

   git clone https://github.com/driftywinds/cbr2cbz.git
   cd cbr2cbz
   

2. Initialize Go module and install dependencies:

   go mod init cbr2cbz
   go get github.com/nwaples/rardecode
   

3. Build for your platform:

   Windows:

   go build -ldflags="-s -w" -o cbr2cbz.exe main.go
   

   Linux:

   go build -ldflags="-s -w" -o cbr2cbz-linux main.go
   

   macOS:

   go build -ldflags="-s -w" -o cbr2cbz-macos main.go
   

4. Cross-compile for other platforms:

   # Windows from Linux/Mac
   GOOS=windows GOARCH=amd64 go build -ldflags="-s -w" -o cbr2cbz.exe main.go
   
   # Linux from Windows/Mac
   GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" -o cbr2cbz-linux main.go
   
   # macOS from Windows/Linux
   GOOS=darwin GOARCH=amd64 go build -ldflags="-s -w" -o cbr2cbz-macos main.go
   

The -ldflags="-s -w" flags reduce the executable size by stripping debug information.

FAQ

Q: What's the difference between CBR and CBZ?
A: CBR files use RAR compression, while CBZ files use ZIP compression. CBZ files are more widely supported and don't require proprietary software to open.

Q: Will this damage my original files?
A: No. The tool only deletes original files if you explicitly choose "yes" when prompted. Until then, both CBR and CBZ files coexist.

Q: Does this work with password-protected CBR files?
A: No, password-protected RAR files are not supported.

Q: Why is the CBZ file sometimes larger than the CBR?
A: RAR typically achieves better compression than ZIP. However, CBZ files offer better compatibility and are easier to work with.

Q: Can I convert CBZ back to CBR?
A: This tool only converts CBR → CBZ. For the reverse, you'd need a different tool.

Dependencies

The project uses the following Go library:

• nwaples/rardecode - RAR archive reading

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Made with ❤️ for comic book enthusiasts