What Is a CBZ File? (And How to Open One Anywhere)

A CBZ file is a ZIP archive of images — the pages of a comic or manga — renamed with a .cbz extension so comic reader apps recognize it. That's the whole format: there's no special encoding, no DRM layer, no text stream. The images inside are ordinary JPEGs or PNGs, named so they sort in reading order, and "CBZ" just means Comic Book Zip. Its siblings follow the same pattern with different compression: CBR is a RAR archive, CB7 is a 7-Zip archive.

How to open a CBZ on a computer

Two routes, both free:

• A comic reader app. CDisplayEx and YACReader on Windows, YACReader or Simple Comic on macOS, and most e-book managers (Calibre included) open CBZ directly, with proper page navigation, two-page spreads and right-to-left mode for manga.
• The rename trick. Because a CBZ is literally a ZIP, renaming volume1.cbz to volume1.zip lets any operating system extract it into a folder of images. You lose the reading interface, but it proves there's nothing exotic inside, and it's a handy escape hatch on a machine where you can't install anything.

Phones and tablets have plenty of free CBZ readers too. On general-purpose screens, the format is a solved problem.

CBZ vs CBR vs CB7

All three are the same idea — an archive of page images — differing only in the compression container:

• CBZ (ZIP): the most compatible, and the safe choice when you have a say in the matter.
• CBR (RAR): equally common in the wild, but RAR is a proprietary format, so some tools handle it less gracefully.
• CB7 (7-Zip): better compression, noticeably worse app support — many readers skip it entirely. More in What Is a CB7 File?.

Comic pages are already-compressed JPEGs, so the container choice barely changes file size. Compatibility is the real differentiator, and CBZ wins.

The part the file-format sites skip: e-readers

Most people searching "what is a cbz file" aren't curious about archive formats — they have one and want to read it, often on an e-ink device. That is where CBZ stops being a solved problem:

• Kindle: no. No Kindle model opens CBZ or CBR, and Send to Kindle rejects them (checked August 2026). Details in Can a Kindle Read CBZ Files?.
• Kobo: opens it, poorly. Kobo firmware displays CBZ natively, but the print-resolution pages get shrunk down, contrast isn't tuned for e-ink, and reading stats don't track. More in Does Kobo Support CBZ?.
• reMarkable and most others: no. Comic archives simply aren't on their format lists.

The fix in every case is the same: convert the CBZ into an EPUB (or KEPUB for Kobo) with pages rebuilt for the exact screen — resized to the device's resolution, contrast-tuned for e-ink, right-to-left order stamped in for manga. That's a rebuild for the screen, not a container swap, which is why renaming the file to .epub doesn't work.

Converting a CBZ for an e-reader

The open-source reference tool for this conversion is Kindle Comic Converter (KCC, github.com/ciromattia/kcc), a desktop app that has done comic-to-e-reader conversion for over a decade. MangaConverter runs the same KCC engine in the browser — free, nothing to install, with a live preview of the converted pages, and self-hostable as kcc-cloud on GitHub. It takes CBZ, CBR, CB7, PDF and EPUB inputs (up to 20 files, 1GB each), offers device profiles for Kindle, Kobo and reMarkable models, and uploaded files auto-delete after 24 hours.

Start from CBZ to EPUB for a general-purpose conversion, or CBZ to Kindle if a Kindle is the destination.

Quick answers

• Is CBZ safe to open? As safe as any ZIP: the risk is in the contents, not the format, and legitimate comic archives contain only images.
• Can I make my own CBZ? Yes — zip a folder of numbered page images and rename the result to .cbz.
• Does CBZ support right-to-left manga? The format itself carries no direction metadata; reader apps let you set it manually, and a proper e-reader conversion stamps it into the output file.

More format guides live on the blog.