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CBR to CBZ
Repackage RAR-based comic books into the universally supported ZIP-based CBZ format with every page pixel-identical
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Lossless: The pages are extracted from the RAR archive and zipped again. No image is decoded, resized or re-compressed.
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Fixes compatibility: Many apps and servers, including Kindle, Kobo, Komga and iOS readers, support CBZ far better than the proprietary RAR format.
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Batch friendly: Upload a whole series; each CBR comes back as its own CBZ in a single download.
You can upload up to 20 ebooks simultaneously.
Comic archives
What happens when a CBR becomes a CBZ
CBR and CBZ contain the same thing: page images in reading order. The only difference is the archive type, RAR versus ZIP. Our converter unpacks the RAR with the official unrar tool and stores the files in a ZIP, so the comic is identical but readable everywhere.
How to use Converter App
1
Upload the CBR files
Single issues or a whole run. The archives can come from your computer or Google Drive.
2
Extract and repack
unrar extracts every page, zip stores them again in the same order with the same names.
3
Download the CBZ
Drop it into your reader or library; it opens exactly like the CBR did, without RAR support.
Key features
Pixel-identical pages
A checksum of each image inside the CBZ matches the one in the CBR, because the image data is copied, not converted.
Open format
ZIP is patent-free and supported by every programming language and operating system; RAR needs a licensed decompressor.
Keeps metadata files
ComicInfo.xml and other sidecar files inside the archive are preserved for Komga, Kavita and ComicRack.
Server-side, no software
No WinRAR, no command line. Works in any browser on any system.
Experience & privacy
Built for reliable document conversion.
Backed by 10+ years of engineering expertise in large-scale data and scientific computing, it’s built for real-world document workflows that require accurate layout preservation, strict privacy, and dependable, high-level performance.
Trusted by Users
Rated 5 stars on Trustpilot for speed, reliability, and ease of use.
User trust
Academic Use
Referenced in published research and used for interview transcription and qualitative data analysis.
Research use
Why CBZ became the standard
CBR and CBZ appeared around 2000 with the CDisplay reader, which simply opened RAR or ZIP files full of scans. RAR was popular then because it compressed slightly better and supported recovery records. Those advantages mean nothing for images that are already compressed, while RAR's licensing kept it out of many apps. Over the following years almost every reader, e-ink device, library server and app store product standardised on CBZ. Converting an old CBR collection is therefore mostly about future-proofing and about reading on devices that never supported RAR.
How the converter repacks the archive
The uploaded CBR is extracted with unrar, the reference decompressor that handles every RAR version including RAR5. All extracted files, pages and any sidecar files such as ComicInfo.xml or cover.jpg, are added to a new ZIP archive with the same names and in the same order, using the store or deflate method; JPEGs are incompressible so the method does not affect size. The ZIP is renamed to .cbz. No image decoding takes place at any point, so the process is lossless and fast even for 200 MB archives.
Managing a comic library after conversion
- Name files consistently: Series v01 (Year) or Series 001 (Year) helps Komga and Kavita group volumes.
- Keep a ComicInfo.xml in each archive if your software writes one; it carries series, number, writer, artist and summary.
- Check a couple of converted issues in your reader to confirm page order before deleting the CBR originals.
- Store the library on a drive with backups; CBZ is durable, drives are not.
Related conversions
If you want to read comics on a Kindle or in a PDF viewer, our CBZ to PDF and CBR to PDF tools render the pages into a document. For readers that only accept EPUB, our CBZ to EPUB converter packs the pages into an e-book with one e-reader-sized page image per chapter. And if you have loose page images, zip them with a numbered naming scheme and rename the archive to .cbz; that is all a comic archive is.
FAQ
Frequently Asked Questions
What is the difference between CBR and CBZ?
Only the compression format: CBR is a renamed RAR archive, CBZ a renamed ZIP. Both hold a sequence of JPEG or PNG pages. Readers that support both treat them identically; readers that support only ZIP cannot open CBR, which is why CBZ has become the de facto standard.
Why do some apps refuse my CBR?
RAR is a proprietary format, and decompression code can only be distributed under RARLAB's licence. Open-source projects and app store apps often leave it out, and RAR5 archives created by recent WinRAR versions are rejected by older libraries entirely. ZIP has no such restrictions, so a CBZ opens everywhere.
Will the quality of the pages change?
No. The image files are copied byte for byte. File sizes also stay the same apart from a few kilobytes of archive overhead, since JPEG and PNG do not compress further in either RAR or ZIP.
My CBR turned out to be a ZIP already. What now?
It happens: some uploaders rename ZIP archives to .cbr. Our converter needs a genuine RAR; if the extraction fails, rename the file to .cbz yourself and it will open in any reader as is.
Are password-protected or multi-part archives supported?
No. Password-protected RARs cannot be extracted without the password, and split archives (.part1.rar, .r00) must be joined on your computer first. Nearly all comic archives are single, unprotected files and convert without issues.
Is the page order preserved?
Yes. The file names are unchanged, and comic readers sort pages by name, so the order is identical to the original. If the original CBR had badly named pages, the CBZ inherits that; a renaming tool fixes it before conversion.