Home

General

Modes

--assist -a

Calculate the filesize of each image format by converting a small sample of pages, then asks you which format to repack the archive with.

--auto -A

Same as --assist, except it automatically picks the best/smallest format to repack the archive with.

Most of the time this will be a .webp. If you wish to exclude this format, you can add --nowebp.

--join -J file1, file2 [, file3, file4, etc]

Concatenate files. Append the contents of n files to the leftmost file, in the order they appear.

Note: to ensure chapters are properly shown in the table of contents when converting to --epub, it is recommended to join all desired files at once (in a single command), instead of doing it one at a time.

Reading/Writing

--dry -d

Dry run. The repacked archive isn't saved at the end, making other options completely safe.

--overwrite -O

Overwrite original archive. Specifically, it will delete the original file, and the new one will be converted to a valid .cbz structure, meaning that non-image files will be discarded.

--force -F

Write even if some files can't be opened or are invalid.

--noprev

Ignore files previously repacked by this program. Recommended when using file pattern globbing (*), specially with --join.

Archive

Ebook profile

--profile, -p PROF

See Ebook Profiles. This is the recommended way of creating fixed-layout EPUB/MOBI files, which you most likely want.

This will influence --size, and implies --epub. This can be overridden by explicitly setting --cbz.

Output format

--epub

Save archive as EPUB.

--mobi

Save archive as MOBI. Requires Kindlegen.

--zip

Save archive as ZIP.

--cbz

Save archive as CBZ. This is the default unless --profile is used.

--unpack (TODO/Unimplemented)

Extract archive contents to a folder

Compression

--compress

Attempt to further compress the archive after packing files. This will have a very negligible effect on file size, and is generally not recommended.

Images

Conversion

--nowebp

Exclude WebP formats from --assist and --auto.

--convert -c format
default: same as source

Format to convert images to. One of: jpeg, png, webp or webpll — png and webpll are lossless. Try -c to get an idea of how they compare, this will vary depending on the source format. Omitting this option will preserve the original format.

--quality 0 - 95
default: 80

Image compression quality for lossy formats, will have a large impact on file size. Smaller values produce smaller files at the cost of visual quality. This option doesn't affect lossless formats.

Notes:
Low values degrade image quality less in WebP than they do in JPEG. Similarly, grayscale images are less affected by this setting that color ones, so generally speaking, you can lower it even more when using --convert webp or --bw to save extra space.
Values higher than 95 will usually increase file size without actually improving quality, and are not recommended.

--size WidthxHeight
default: don't rescale

Rescale images to the specified resolution, using Lanczos interpolation. Does its best to detect and preserve landscape images.

Add --noup to disable upscaling, so images can only be downscaled (as long as they're greater than value).

Add --nodown to disable downscaling, so images can only be upscaled (as long as they're less than value).

Note: this isn't magic. Please don't upscale a low quality source to upload to manga sites and claim yours is higher quality, because it isn't, and it will annoy people.

--bw

Convert images to grayscale. Useful for e-Paper screens, reducing file size by another 10% to 20%. Provides no benefit to comics which only have a few coloured pages (manga).

--color

Don't automatically convert images to grayscale when using --profile.

Other

Performance

--processes 1 - 32
default: Core count - 1 (close to 100% utilization)

Max number of processes to spawn. This will only improve performance if your CPU has cores to spare (it's not magic!).

Warning: May choke lower end systems, set this to 2 or 4 if you're experiencing high memory usage.

--sequential

Disable multiprocessing altogether. Use this only if you're still experiencing memory issues, or for debugging.

Diagnostic info

--verbose -v

More progress messages. Can be repeated (-vv) for debug output.

--silent -s

Disable progress messages.

--config

Print current settings and path to configuration file and exit.

--version

Print current version and exit.