How to convert CBZ to EPUB without uploading it
Every "free" online CBZ-to-EPUB converter you've used uploads your comic to a company server, converts it there, and — in several documented cases — keeps a copy or a live download link for days, or limits free users to a few conversions a month. For comics you bought, scanned yourself, or simply wouldn't post publicly, that's an unnecessary risk. The safer approach is to convert the file where it already is: on your own device.
This tool does exactly that. When you drop a CBZ here, your browser:
- Checks the file is really a ZIP-based archive — by its magic bytes, not its name — so a JPEG renamed .cbz is refused with a clear message, and a CBR (a RAR archive) is refused with an explanation instead of a cryptic error. A real archive saved with the wrong extension still converts.
- Unzips it in memory and sorts the pages in natural order — page 2 before page 10 — reading nested folders in order and skipping ComicInfo.xml, text notes, macOS entries and hidden files, listing everything it skipped on the archive card.
- Builds a real EPUB 3 ebook by hand — mimetype first and uncompressed, a container file, package metadata with the archive filename as the book title, a navigation document, a table of contents, and one fixed-layout page per image. JPG, PNG and single-frame GIF pages go in unchanged; every other format is rasterized to JPEG on the device first.
What makes this converter different
The pages that top the results for this search mostly convert on a server (MangaConverter runs its KCC engine in the cloud and caps free conversions at several per month, 101convert caps free files at 10 MB and three at a time, and Zamzar is server-side with a 50 MB cap), and the desktop options — Calibre and go-comic-converter — are installs, not browser tools. This page is the only dedicated CBZ-to-EPUB page we found that converts fully in the browser: no upload, no monthly cap, no account, no 10 MB limit, a batch of 20 archives, plain .zip archives of page images accepted too, and a live network-request counter so you can verify the privacy claim yourself. It runs entirely in your browser — there is no server to upload to.
When is CBZ-to-EPUB the right choice?
Whenever a comic or manga archive belongs on an e-reader: a CBZ you bought or scanned that you want to read on a Kindle (via Send to Kindle), a Kobo or Apple Books, a manga volume to read right-to-left, or a set of scanned pages to keep as one book instead of a folder of images. An EPUB keeps the pages in order, with a title your reader shows in its library, where a folder of images would arrive scattered. If the destination wants a document for printing or forms, convert to PDF instead — an EPUB is a book, not a print file.
Honest limitations
No text layer
The EPUB pages hold pictures, not text. The book is not searchable, and you cannot select or copy words from it. Run the pages through OCR beforehand if you need searchable text.
No quality recovery — and no loss for JPG/PNG/GIF
JPEG throws away detail when it compresses, and embedding cannot put it back. But nothing is lost either for JPG, PNG and single-frame GIF: the source bytes go into the EPUB unchanged. Rasterized formats are re-encoded once, at the quality you choose.
Fixed layout
Every page is exactly the size of its image (pre-paginated). Kindle, Kobo and Apple Books handle that well; some smaller readers show fixed-layout pages smaller than the screen or ignore the fixed size.
First frame only
Animated GIFs keep their first frame and HEIC sequences keep their first still — an EPUB page is a still image. A multi-page TIFF is the exception: it becomes one page per TIFF page.
Metadata is stripped
ComicInfo.xml and text notes inside the archive are skipped, and camera metadata (EXIF, including location) is dropped when a page is embedded or rasterized. The orientation tag is read and applied first, so the output is stored upright. Only the book title, author and language you set are kept.
CBR, CB7 and encrypted archives
CBR is a RAR archive and CB7 is a 7z archive — neither opens in this tool, which reads ZIP-based CBZ only. Password-protected (encrypted) archives are refused too. Convert those formats to CBZ first, without a password, then convert them here.