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CBZ to EPUB
Turn a CBZ comic archive into an EPUB e-book for Kindle, Apple Books, Google Play Books and reading apps that cannot open comic archives
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calibre comic engine: The pages are processed by calibre's comic input plugin and written as a standard EPUB with a cover, a table of contents and one page per chapter.
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Made for e-ink readers: Each page is scaled to about 584 by 754 pixels and converted to grayscale, which matches 6-inch e-readers and makes the EPUB about 85 percent smaller than the CBZ.
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Know the trade-off: Colour and full resolution are not kept. For colour comics on a tablet, keep the CBZ or use our CBZ to PDF converter instead.
You can upload up to 20 ebooks simultaneously.
Comic archives
What the converter does with a CBZ
A CBZ is a ZIP archive of page images in reading order. calibre's ebook-convert unpacks it, sorts the pages by file name, normalises each image for an e-reader screen and wraps every page in its own XHTML chapter of an EPUB 2 file. The result opens in any EPUB reader and on every Kindle via Send to Kindle.
How to use Converter App
1
Upload the CBZ
Single issues, volumes or scanned picture books from your computer or Google Drive. Several archives are converted one after another.
2
Pages become chapters
Images are ordered by name, scaled to the e-reader page, converted to grayscale and stored as PNG. Wide double-page spreads are split into two pages.
3
Download the EPUB
Send it to your Kindle, open it in Apple Books or Google Play Books, or drop it into calibre's library.
Key features
Cover and table of contents
The first page becomes the cover, kept in colour at up to 1200 by 1600 pixels, and a navigation list with one entry per page is generated.
Small files
In our test a 65 MB archive with 30 pages of 1988 by 3056 pixels became a 9.8 MB EPUB in about six seconds.
Standard EPUB 2
Plain XHTML pages, NCX table of contents and OPF manifest. No DRM, no app-specific extensions, so the file works in every reader we know of.
Honest about resolution
The 584 by 754 pixel pages are sharp on a 6-inch e-ink screen but soft on a 10-inch tablet. We say so here rather than letting you find out after converting.
Experience & privacy
Built for reliable document conversion.
Backed by 10+ years of engineering expertise in large-scale data and scientific computing, it’s built for real-world document workflows that require accurate layout preservation, strict privacy, and dependable, high-level performance.
Trusted by Users
Rated 5 stars on Trustpilot for speed, reliability, and ease of use.
User trust
Academic Use
Referenced in published research and used for interview transcription and qualitative data analysis.
Research use
CBZ and EPUB: two containers for very different things
A CBZ is nothing more than a ZIP file full of page images, usually JPEG or PNG, named so that they sort in reading order. It carries no text, no table of contents and no metadata beyond an optional ComicInfo.xml. An EPUB is also a ZIP, but one with a defined structure: an OPF manifest listing every file, a reading order called the spine, XHTML chapters with CSS, and a navigation document. Converting a comic therefore means building that structure around the pages: each image becomes a chapter that contains a single picture, the first image becomes the cover, and a navigation list is generated. The reader then treats the comic like any other book, including syncing the reading position and showing it in the library with a cover.
How calibre's comic pipeline processes the pages
Our server runs ebook-convert from calibre inside a container. Its comic input plugin extracts the archive, sorts the images by file name and runs each one through a normalisation step that was designed for e-ink screens: the image is converted to grayscale, trimmed, scaled to the output profile's page size and saved as PNG. The default profile gives pages of 584 by 754 pixels. Wide images are split into two pages. The EPUB output plugin then writes an EPUB 2 package with one XHTML file per page, a title page that shows the cover as scalable SVG, an NCX table of contents and zero page margins. In our measurements a 30-page archive of 65 MB produced a 9.8 MB EPUB in about six seconds; a four-page sample of 60 KB produced a 425 KB EPUB because the colour cover is larger than the downscaled pages.
When to convert and when to keep the archive
- Kindle Paperwhite, Basic, Oasis: convert. The grayscale 6-inch pages are a near-perfect match, and Send to Kindle delivers the EPUB wirelessly.
- Kindle Scribe and large e-readers: the pages are upscaled and look soft; a higher-resolution route is CBZ to PDF, which keeps colour and the same page layout.
- Kobo and PocketBook: open the CBZ directly, no conversion needed.
- Phones and tablets: use a comic app with the CBZ, or convert to PDF for colour. EPUB is only worth it when the comic has to live in a book app such as Apple Books.
- Archiving: always keep the original CBZ. The EPUB is a reduced reading copy, not a replacement.
Related tools
If your archive is a CBR, our CBR to CBZ converter repacks it losslessly first, and CBR to EPUB converts it directly. CBZ to PDF produces a colour PDF with the same reduced page size for tablets and phones. EPUB to CBZ goes the other way and renders an e-book's pages to images. And for loose page images, any ZIP tool creates a CBZ: zip the files with numbered names and rename the archive.
FAQ
Frequently Asked Questions
Which devices need this conversion at all?
Fewer than you might think. Kobo and PocketBook e-readers open CBZ files directly, and comic apps such as Panels, Chunky, CDisplayEx or Komga read them natively. The conversion is for readers that only accept e-book formats: Kindle devices and apps, Apple Books, Google Play Books, library and school platforms, and e-readers whose comic support is missing or slow. If your device opens CBZ natively, keep the archive; you lose nothing.
Will the pages be in colour?
No. calibre's comic pipeline converts the pages to grayscale by default, which is what we run. In our test a red-to-yellow gradient page came out as a 233-level grayscale PNG. The cover is the exception: it is stored in colour at up to 1200 by 1600 pixels. For colour comics on a phone, tablet or colour e-ink device, our CBZ to PDF converter keeps colour, or simply read the CBZ in a comic app.
What resolution do the pages have?
About 584 by 754 pixels, regardless of the source size: 1988 by 3056 pixel scans were reduced to that size in our test. This matches the 600 by 800 panel of 6-inch e-readers and is the reason the EPUB is roughly 85 percent smaller than the archive. On a large tablet or a monitor the pages look soft, and small lettering in dense manga panels can become hard to read. For full-resolution pages, keep the CBZ.
How are double-page spreads handled?
Landscape images that are wider than they are tall are split into two portrait pages, left half first, so each half fills the e-reader screen. Right-to-left manga reads the spread in the wrong order after the split; in that case keep the CBZ in a reader with right-to-left support.
How do I get the EPUB onto a Kindle?
Email it to your Send to Kindle address or use the Send to Kindle app or web page; Amazon has accepted EPUB since 2022 and converts it for the device. For USB transfer, convert the EPUB further to AZW3 with our EPUB to AZW3 tool, because Kindles do not open sideloaded EPUB files. Kindle does not accept CBZ in any of these ways, which is the main reason this converter exists.
Does the converter keep the page order and metadata?
The page order follows the file names inside the archive, the same rule every comic reader uses. The book title is taken from the archive file name and the author is set to Unknown; a ComicInfo.xml inside the archive is not read. You can edit title, author and series in calibre or in your reader app afterwards.