Rohman
A manga volume as a PDF is a strange object. Every page is a picture of a page, but it's wrapped in a format built for documents: page boxes, embedded fonts, vector drawing, a text layer nobody needs. Your comic app has to lay out each page like a report before it can show you a drawing.
A CBZ skips all of that. It is the drawings, in order, in a zip file. Converting is mostly about getting the pages out at the right size, and the right size is smaller than most people pick.
Quick answer: To convert a PDF to CBZ, render each page to a JPEG at a resolution close to your e-reader's screen and pack the images, in order, into a zip with a .cbz extension. PDF to CBZ does this in your browser: pick 150 or 200 DPI and quality around 85%, convert, and copy the .cbz to your Kobo or KOReader device. Kindle doesn't accept CBZ, so for Kindle keep the PDF or use a Kindle-specific converter.
What Is Actually Inside a CBZ File
Rename a .cbz to .zip, open it, and you'll see it: a folder of images. That's the whole format. Wikipedia describes a comic book archive as "a type of archive file for the purpose of sequential viewing of images," an idea popularised by David Ayton's CDisplay viewer. The Z means zip; CBR is the same thing packed with RAR, and CB7 uses 7-Zip.
There's no page list inside. A reader shows the images sorted by filename, which is why naming matters more than anything else in the file. Name pages page-1.jpg through page-12.jpg and a plain alphabetical sort puts page 10 right after page 1. Zero-padding fixes it: page-001.jpg, page-002.jpg and so on sort correctly in every reader. That's the scheme PDF to CBZ uses.
An archive can also carry a ComicInfo.xml file at its root, an optional metadata format that started in ComicRack and is now maintained by the Anansi Project. It holds series, issue number, volume and credits, and its Manga field can be set to YesAndRightToLeft so a reader that understands it flips pages the Japanese way. Library apps use it to sort a collection. A CBZ without one still opens everywhere.
Which Readers Want CBZ, and Why Kindle Doesn't
Before converting anything, check that your device actually wants the file.
| Where you read | CBZ support | What to do |
|---|---|---|
| Kobo e-readers | Yes, native, alongside CBR | Copy the .cbz over USB |
| KOReader (on Kobo, PocketBook, Android and others) | Yes, a fixed-page format | Copy the .cbz into your library folder |
| Kindle via Send to Kindle | No | Send the PDF, or convert to a Kindle format |
| Desktop and tablet comic apps | Almost always | Open the .cbz directly |
Kobo's format support page lists "Comic Books: CBZ and CBR" for its e-readers. The Kobo Books app for Android is a different story: its list covers EPUB variants and MOBI, not comics, so this is an e-reader answer. The KOReader README lists CBZ with PDF and DjVu as its fixed-page formats.
Amazon is the exception. The Send to Kindle help page lists HTML, RTF, TXT, JPEG, GIF, PNG, BMP, PDF and EPUB, and nothing else. No CBZ. If you read on a Kindle, converting to CBZ makes things worse, not better. Either send the PDF, or use a tool built for the job like Kindle Comic Converter, which builds Kindle-native files from comics and can take a PDF as input.
Pick the Resolution for Your Screen, Not the Maximum
This is the setting people get wrong, in the expensive direction. The tool offers 72, 150, 200 and 300 DPI, and 300 sounds like the safe choice. For an e-reader it usually isn't.
DPI here means pixels per inch of the PDF page. The pixel size of each image is the page size multiplied by the DPI. For a PDF laid out at a standard US comic size of about 6.6 by 10.25 inches, that works out to:
- 72 DPI: about 477 × 738 pixels. Fine for a phone, soft on anything else.
- 150 DPI (the default): about 994 × 1538 pixels.
- 200 DPI: about 1325 × 2050 pixels.
- 300 DPI: about 1988 × 3075 pixels, more than twice the pixels of 200.
Now compare that with the screen. A Kobo Libra Colour, according to Kobo's spec sheet, is 1264 × 1680 pixels, 300 PPI for black and white and 150 PPI for color. 150 DPI comes in a little under the screen and 200 DPI a little over it. At 300 DPI the device throws away more than half of every page's pixels when it scales the image down to fit, and you carry that weight in storage and page-turn time for nothing.
One catch: not every comic PDF uses a real-world page size. Some tools that build PDFs from scans size each page at 72 pixels to the inch, so a high-resolution scan becomes a page 20 or 30 inches tall. At 150 DPI you'd get enormous images. Check first with the Page Size Inspector. If the pages read as poster-sized, drop to 72 DPI; you'll still get roughly the scan's native pixels back.
JPEG Quality, and Compressing Twice
PDF to CBZ renders each page fresh and saves it as a JPEG. It doesn't dig out the original image files embedded in the PDF. That's the right call for PDFs made from artwork files or digital exports, where there is no single "original image" per page. It has a cost for PDFs built from scans that were already JPEGs: those pages are compressed a second time.
At the default quality of 85%, the second pass is hard to see on an e-ink screen, especially on black-and-white manga. Push the slider toward 60% and you'll start to see smudgy halos around line art and speech bubbles, because sharp black-on-white edges are exactly what JPEG handles worst. If you're archiving a colour comic rather than just reading it, go to 90–95%, or reach for Kindle Comic Converter, whose README says it reads PDFs by "only extracting JPG images," which keeps the originals untouched.
A smaller file isn't guaranteed either. A PDF of scanned JPEGs converted at a higher resolution than the scans can come out bigger as a CBZ. A PDF with vector artwork will almost always get bigger, because a drawing that was a few kilobytes of paths becomes a full picture per page. Converting pays off in how the file behaves on the device, not always in megabytes.
How to Convert a PDF to CBZ with OxygenPDF
- Open PDF to CBZ and drop in the PDF. You can add several volumes at once and they'll all convert with the same settings.
- If the PDF is password-protected, enter the password when asked.
- Set Resolution. Use 150 DPI for most e-readers and phones, 200 DPI for large screens like 7- to 8-inch readers and tablets, and 300 DPI only if you plan to print.
- Set Quality. Leave it at 85% for reading; raise it for colour art you care about.
- Convert and download. You get one
.cbzper PDF, named after it, with every page aspage-001.jpg,page-002.jpgand so on. - Connect your Kobo by USB and copy the file onto it, or drop it into KOReader's books folder. It shows up in your library with no further conversion.
Every page of the PDF goes in, including covers and blank pages. If you want to drop a credits page or an ad insert first, remove those pages with Delete Pages before converting.
Before and After the Conversion
A few things make the result noticeably better on e-ink.
Fix faint scans first. Grey paper and thin pencil lines turn muddy on an e-ink screen. The e-Ink Optimizer bleaches grey backgrounds and thickens faint strokes in the PDF. Run it, then convert the cleaned PDF to CBZ.
Add metadata if you keep a library. PDF to CBZ doesn't write a ComicInfo.xml. If you want series and issue sorting, or right-to-left reading set in the file itself, add one afterwards with a comic library manager. For reading one volume at a time, you can skip it and set the reading direction in your reader.
Going the other way. If someone sends you a CBZ and you need a PDF, for printing or a device that only reads PDF, CBZ to PDF puts the pages back into one file in reading order.
Your Comics Stay on Your Machine
Comic files are big, and uploading a 300 MB volume to a converter just to download it again is slow even when the site is trustworthy. PDF to CBZ renders the pages in your browser tab and builds the zip there, so the file never leaves your computer and the only limit is your own memory. The reasons we build every tool this way are in why local-first PDF tools. If you only want individual page images rather than an archive, PDF to JPG exports them loose; the PDF to JPG guide covers the settings.
Frequently Asked Questions
Can I read CBZ files on a Kindle?
Not through Amazon's own tools. Send to Kindle doesn't accept CBZ. Send the PDF instead, or convert the comic into a Kindle format with a dedicated converter such as Kindle Comic Converter.
What DPI should I use to convert a PDF to CBZ?
Match your screen. For a comic-sized page, 150 DPI gives about 1,000 pixels across, right for most 6-inch readers and phones; 200 DPI gives about 1,300, a good fit for 7- and 8-inch readers. Higher settings mostly make files bigger.
Is a CBZ smaller than a PDF?
Sometimes. A PDF of scanned images converted near the scans' resolution usually ends up similar in size or smaller. A PDF with vector artwork, or one converted at a high DPI, usually gets bigger.
Does converting PDF to CBZ lose quality?
Each page is re-rendered and saved as a JPEG, so there's one round of compression. At 85% quality or above it's hard to see on an e-reader. If the PDF already holds JPEG scans and you're archiving them, use a higher quality setting.
How do I make a manga CBZ read right to left?
Set the reading direction in your reader app, or add a ComicInfo.xml with the Manga field set to YesAndRightToLeft for readers that honour it. The CBZ from PDF to CBZ doesn't include metadata, so the reader's setting is the quickest fix.
Ready to read that volume the way it was drawn? Convert your PDF to CBZ in your browser. Nothing is uploaded.
