Free CBZ Converter: No Sign-up, Files Never Uploaded
This free CBZ converter runs entirely on your device. You do not need an account or a login, and your files are never uploaded, so they never leave your browser.
Comic book (CBZ) in short. A ZIP archive of page images, read by comic book apps. Pages are plain images, so no text can be reflowed.
From CBZ you can convert to EPUB and PDF. These pairs run on code already in the page, with no extra engine to download.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Add your CBZ files by dragging them onto the converter or by using the file picker.
- Choose the format you want from the list of targets that fit your file.
- Open the options if you want to change quality or size, or keep the defaults.
- Press Convert and watch the progress shown for each file.
- Download each result, or take them all together as one ZIP when you converted several files.
Features
- Reads .cbz files and can also write them.
- Free, with no watermark added to the result.
- No sign-up and no login.
- Your files are never uploaded and never leave your device.
- Batch conversion with a ZIP download for several results.
- The input is recognised by its content, not only by its file name.
- 2 target formats to choose from.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| PDF.pdf | Yes | Yes | Fixed-layout document format that looks the same on every device. |
| Markdown.md | Yes | Yes | Plain text with light markup for headings, lists, links and emphasis. |
| HTML.html | Yes | Yes | The markup language of web pages. |
| Plain text (TXT).txt | Yes | Yes | Unformatted text with no styles, images or layout. |
| EPUB.epub | Yes | Yes | The open standard for e-books; text reflows to fit any screen size. |
| MOBI.mobi | Yes | No | MOBI is a legacy format superseded by KF8 and EPUB; Kindle accepts EPUB, so MOBI can be read but not created. |
| AZW3 (KF8).azw3 | Yes | No | AZW3 is Amazon’s proprietary format; Kindle accepts EPUB, so AZW3 can be read but not created. |
| FictionBook (FB2).fb2 | Yes | Yes | XML e-book format popular in Russian-speaking countries. |
| Comic book (CBZ).cbz | Yes | Yes | A ZIP archive of page images, read by comic book apps. |
About the formats
About CBZ
A ZIP archive of page images, read by comic book apps.
Pages are plain images, so no text can be reflowed.
It does not support transparency.
What CBZ can become
CBZ to EPUB runs in the page. Each page image becomes one page.
CBZ to PDF runs in the page. Each page image becomes one page.
Privacy: how it works
- Your CBZ files stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
Tips
- Check chapter breaks and images in the result before you copy it to your reader.
- DRM-protected books cannot be converted, so use files you own without protection.
- Pick the format your reader supports natively; EPUB is the safest choice for most apps.
- Keep the original file in case a cover or a table looks different after conversion.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your CBZ files are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.
What can I convert CBZ files to?
You can convert CBZ to EPUB and PDF. Pick one on the converter and it applies to every file you add.
Can I convert other files to CBZ?
Yes, where a source format supports it. Open the converter and look for CBZ in the list of targets.
Can I convert many CBZ files at once?
Yes. Add as many files as your device can handle. Each one is converted on its own and you can download them one by one or as a single ZIP.