Free online PUB to CBZ converter

Comic-reading apps often accept CBZ files but not Microsoft Publisher documents. Converting a PUB publication to CBZ makes each page available as an image in a comic archive; the pages must be rendered, so the result is not editable like the original layout.

What the PUB format is

PUB is Microsoft Publisher’s page-layout format, used for publications such as brochures, newsletters, and booklets. You typically encounter it when someone shares a Publisher project; Microsoft Publisher is the program used to open and edit it.

What the CBZ format is

CBZ is a ZIP archive containing sequentially named page images, commonly JPEG or PNG. Comic-book readers can display its pages in order, and the archive keeps a set of images together as one file.

How to convert PUB to CBZ

Online on 101convert.com

1. Upload the PUB file to the converter on the page.
2. Choose CBZ as the output format and start the conversion.
3. Download the converted file. Several files can be converted in one batch; check the page for the per-file size limit.

Offline with desktop software

Microsoft Publisher can export the publication to PDF. Then use the free Poppler utility, available for Windows, macOS, and Linux, to render the PDF pages, and Python 3 to package them in page order.

1. In Publisher, open the file and choose File → Export → Create PDF/XPS Document. Save it as book.pdf.
2. In a terminal in the PDF’s folder, render the pages as JPEG images. The example uses 150 dpi; increase the resolution for finer detail or reduce it for smaller images.

pdftoppm -jpeg -r 150 book.pdf page

Run this Python script in the same folder to create a CBZ with zero-padded page names, which preserve the correct order:

from pathlib import Path
from zipfile import ZipFile, ZIP_DEFLATED

pages = sorted(Path('.').glob('page-*.jpg'),
               key=lambda p: int(p.stem.rsplit('-', 1)[1]))
with ZipFile('book.cbz', 'w', ZIP_DEFLATED) as archive:
    for number, page in enumerate(pages, 1):
        archive.write(page, f'{number:04}.jpg')

Quality and limitations

CBZ stores page images rather than Publisher layout data: text is not searchable or selectable, and links and editable objects are not retained. Check the rendered pages for clipping and choose a resolution that balances legibility against archive size.