Free online JPG to CBZ converter

Comic readers and ebook apps may require a CBZ archive instead of a folder of separate scanned pages. Packaging the JPG files into CBZ creates one shareable, readable book without re-encoding the images.

What the JPG format is

JPG, also written as JPEG, is a lossy raster-image format used by cameras, scanners, phones, document-scanning software, web browsers, and image editors such as Photoshop, GIMP, and Affinity Photo. Scanned comic pages, photographed artwork, and exported ebook illustrations commonly use .jpg or .jpeg.

Each JPG file contains one image and has no built-in page number, reading order, comic metadata, or searchable text. JPEG compression reduces file size by discarding image information; repeatedly opening and resaving a JPG can add blocking, ringing, and other artifacts.

What the CBZ format is

CBZ is a comic-book container made from a ZIP archive. It normally contains sequentially named page images, usually JPG or PNG files. The .cbz extension tells comic readers to treat the ZIP contents as an ordered book; the archive remains a standard ZIP internally.

CBZ combines a page set into one file for compatible readers such as CDisplayEx, YACReader, ComicRack, Calibre, Komga, and many mobile reading apps. Readers can provide thumbnails, single- or double-page display, zooming, and reading-position tracking. Optional files such as ComicInfo.xml can store metadata, but they are not required.

CBZ does not provide reflowable text, selectable text, OCR, or a universal table of contents. OCR must be performed separately if text in the page images needs to be searched or copied. Manga reading direction is usually an application setting rather than a property guaranteed by the CBZ file.

Convert the pages with 101convert.com

You can use the built-in converter on 101convert.com for free without installing software. Add all JPG pages for one book, select CBZ as the output format, start the conversion, and download the resulting archive. Check the page order before submitting a multi-page set and test the downloaded CBZ in the intended reader.

Create a CBZ manually

1. Put the pages for one book in a separate folder. Remove thumbnails, unrelated images, and hidden operating-system files such as Thumbs.db.
2. Rename the pages with fixed-width numbers, for example 001.jpg, 002.jpg, and 010.jpg. Place the cover at the first number. Fixed-width names prevent lexical sorting from placing page 10 before page 2.
3. Select the page files themselves, not their containing folder, and create a ZIP archive. In 7-Zip, use 7-Zip → Add to archive, set Archive format to zip, and choose Store or compression level 0. JPG is already compressed, so ZIP compression usually saves little space.
4. Name the archive with the .cbz extension, such as my-comic.cbz. If the program creates my-comic.zip, enable file-extension display in the file manager and rename only the final extension.
5. Open the CBZ and check the cover, page order, final page, orientation, and readability.

On macOS or Linux, an equivalent command is:

zip -0 ../my-comic.cbz 001.jpg 002.jpg 003.jpg

On Windows with 7-Zip installed, use:

7z a -tzip -mx=0 my-comic.cbz 001.jpg 002.jpg 003.jpg

Use the complete ordered filename list when names contain spaces, mixed extensions, or shell-special characters. A pattern such as page-*.jpg is suitable only when the filenames sort in the intended order. Keep the images at the archive root rather than inside an extra outer folder; root-level pages have the broadest reader compatibility.

Quality and compatibility limits

Creating a CBZ copies the existing images into an archive; it does not increase resolution, remove JPEG artifacts, or create an editable source. Keep the original JPG files for later cropping, retouching, rescanning, or conversion. Do not decode and resave the pages as JPG merely to create CBZ, because that adds another generation of JPEG loss.

Very large scans can consume substantial memory on mobile readers, while excessive resizing can make page text unreadable. Preserve enough resolution for the target display and avoid changing dimensions unless the reader or device has a specific limit.

Most readers support standard RGB JPG files, but some have problems with malformed images, unusual filename characters, CMYK color, progressive encoding, mixed page formats, or unsupported image extensions. If a page fails to display, re-export that page as a valid RGB JPG or PNG, then recreate and retest the archive. JPG and PNG pages can coexist in a CBZ, but consistent naming and dimensions reduce reader-specific problems.