How do you convert PDF, EPUB or CBR files to CBZ?

What converting to CBZ actually does

A CBZ is a ZIP archive holding the pages of a comic as image files, renamed so comic readers know to open it as a comic. What is a CBZ file, and how do you read one? covers the format itself. Converting means getting the page images out in order and zipping them. The zipping is easy. The order is where conversions go wrong.

So think first about whether you need a conversion at all. You do not need to convert a file the reader already opens; if the app you read in already opens the PDF or CBR in front of you, leave it as it is. Convert when the reader wants CBZ, or when the file is heading somewhere that only takes CBZ.

If you were planning to use Calibre: its manual FAQ lists CBZ among its input formats and does not list CBZ among its output formats, so its own documentation does not claim it converts anything to CBZ. Worth knowing before you queue up a batch in it.

Tools change their format lists; the linked pages have the current wording. Checked 2026-10-01.

CBR to CBZ

A CBR holds a RAR archive. The page files are copied as they are into a new ZIP. Renaming the .cbr to .cbz does not convert it: the archive inside is still a RAR.

Two documented ways to run the extraction and the zipping. 7-Zip's own site lists RAR among the formats it unpacks and ZIP among the formats it packs and unpacks. The systems' own ZIP support works too: Microsoft's Zip and unzip files page describes "Show more options > Send to > Compressed (zipped) folder" for the zip step, and the same page's FAQ says Windows 11, version 24H2 supports ZIP, RAR, 7z and TAR archive formats. Apple's Zip and unzip files and folders on Mac page describes the Compress command, and says: "If you compress a single item, the compressed file has the name of the original item with the .zip extension."

1. Extract the RAR.
2. Check the page order by file name before you zip anything.
3. Zip the page files. Select the images themselves, not the folder above them. Microsoft's and Apple's pages above are the final word on their own menu steps.
4. Rename the .zip to .cbz.

Checked 2026-10-01 against 7-Zip's site, Microsoft's help page and Apple's help page.

PDF to CBZ

For a PDF there are two documented jobs: extracting the stored images, and rendering pages. MuPDF's mutool extract documentation says the command "can be used to extract images and font files from a PDF file", and that "the image and font files will be saved out to the same folder which the file originates from". It saves the image and font files out to the folder the file is in. The same page adds: "If no object numbers are given on the command line, all images and fonts will be extracted from the file".

MuPDF's mutool draw documentation takes the other route: the command "will render a document to image files", and its -r option renders "the page at the specified resolution". The same page shows how to name them: the -o output name can "Embed %d in the name to indicate the page number", and printf modifiers are supported, "%03d" being its example, which zero-pads the number in the file name. The same page puts the default resolution at 72 dpi, so give -r a higher value when you render comic pages.

Which one you want depends on the PDF. For a PDF whose pages are stored images, pull the page images out. Otherwise render each page to an image at a resolution you choose.

Then the tail is the same as for a CBR: check the file names sort into reading order, zip the images, and rename the .zip to .cbz. The next section covers the naming.

Commands and options as documented on MuPDF's own pages, checked 2026-10-01.

EPUB to CBZ

The W3C's EPUB 3 specification says an OCF ZIP container, the file that carries an EPUB publication, "is a container technology based on the zip archive format". It adds: "Since an OCF ZIP container is fundamentally a ZIP file, commonly available ZIP tools can be used to extract any unencrypted content stream from the package." So you need no converter to get inside one: unzip the EPUB and you have its files.

For an image-based comic EPUB, the pages are inside it, in the order its package lists. The same specification says "The spine element defines an ordered list of manifest item references that represent the default reading order." The package document holds that list. Go through the spine's pages in order, take the image each page shows, check the names, zip them, and rename the .zip to .cbz.

A text-based EPUB is not a comic, and converting one to CBZ does not make sense: read it as the EPUB it is.

Wording from the W3C EPUB 3 specification, checked 2026-10-01.

Page order and file names

Whichever route you took, the last mile decides whether readers show the comic in order. Name the files with zero-padded numbers so every reader sorts them the same way. That means 001, 002, 010 rather than 1, 2, 10. MuPDF's own documentation gives "%03d" as its printf example when naming rendered pages.

Do not expect a smaller file. Microsoft's help page says "Some types of files, like JPEG images, are already highly compressed", and that if you zip several JPEG pictures into a folder, "the total size of the folder will be about the same as the original collection of pictures". Zip the pages to carry them in one file, not to shrink them.

A ComicInfo.xml with the comic's details is optional. A CBZ without one reads fine. How do you organize a digital comic collection? covers the tagging and the folder layout when the whole collection needs it.

Naming idea from MuPDF's documentation, the compression note from Microsoft's page. Checked 2026-10-01.

Reading the result on Android

Copy the CBZ to the phone and import it. Easemic is a free Android app, in invite-only testing, open source later. It imports CBZ and plain ZIP archives and folders of images from the phone. It does not open CBR, CB7 or PDF.

Imported comics are your own files: they read offline, they are never uploaded to storage, and the export leaves them out. On a new phone, copy the folder over and import it again. How do you move a comic library to a new phone? covers that move and the rest of a library.

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