How to convert CBR to CBZ (and fix RAR5 comics)

The short answer

A CBR is a RAR archive of images; a CBZ is a ZIP archive of the same images. To convert one to the other you extract the CBR into a folder, compress the images into a ZIP, and rename the result from .zip to .cbz. The pictures are not re-encoded, so the quality is identical to the original.

Renaming a .cbr straight to .cbz does not work. The extension changes but the contents are still RAR, and most readers will reject it.

Why convert at all: RAR5

RAR comes in two versions you will meet in comic files. RAR4 is the older one; RAR5 is what recent versions of WinRAR produce by default. Plenty of comic readers, particularly on phones, read RAR4 but not RAR5. TritonPanels is one of them: a RAR5 CBR fails to import with a message that it may be corrupted, password-protected or built with an unsupported RAR variant. You can’t tell RAR4 from RAR5 by the file name, so if a CBR that opens fine on your computer will not import on your phone, assume RAR5 and convert it.

CBZ also has the widest support of any comic format. Converting a collection once means it works in every reader and on every server you might move to later.

On Windows

1. Extract the CBR. Recent versions of Windows 11 can open RAR archives in File Explorer; otherwise use a free archiver such as 7-Zip. Because the file ends in .cbr, Windows may not recognise it: either rename a copy to .rar first, or right-click it and open it with the archiver directly. Extract into a new, empty folder named after the comic.
2. Open the folder and check it. You should see the page images directly, or one folder containing them. Delete anything that is not a page or ComicInfo.xml — text files, thumbnails, adverts the uploader added.
3. Compress the pages. Select the page images (and ComicInfo.xml if there is one), right-click, and choose Compress to ZIP file. On older Windows versions it is Send to › Compressed (zipped) folder.
4. Rename the new .zip to .cbz. If you can’t see extensions, turn on File name extensions in File Explorer’s View menu first, or you will end up with comic.cbz.zip.

With 7-Zip you can do step 3 in one go: select the files, choose 7-Zip › Add to archive, set the format to zip and type the archive name ending in .cbz.

On a Mac

1. Extract the CBR. The Archive Utility built into macOS does not open RAR, so install a free unarchiver such as The Unarchiver or Keka. Open the CBR with it and extract into a new folder.
2. Check the folder as above and remove anything that is not a page or ComicInfo.xml.
3. Compress the pages. Select the images in Finder, right-click and choose Compress. Finder names the result Archive.zip.
4. Rename it to the comic’s name with a .cbz extension, and confirm when Finder asks whether to change the extension.

Finder can add a hidden __MACOSX folder to a ZIP. Most readers ignore it, but if a reader ever shows blank or broken extra pages, build the archive from Terminal instead, as below.

From the command line

If you have more than a handful of comics, the command line is quicker and more predictable. With 7-Zip installed (7z on Windows, or the 7zz or 7z package on macOS and Linux), extract a CBR into a folder:

7z x "Comic 001.cbr" -o"Comic 001"

Then, from inside that folder, put its contents into a new CBZ:

cd "Comic 001"
7z a -tzip "../Comic 001.cbz" *

On macOS and Linux the standard zip tool works too; -X leaves out the extra file attributes that create the __MACOSX clutter:

cd "Comic 001"
zip -r -X "../Comic 001.cbz" .

JPEG and PNG pages are already compressed, so the ZIP will be about the same size as the CBR. That is expected; it is not a sign that anything went wrong.

Getting the page order right

A CBZ has no table of contents. Readers show the pages in filename order, so the names are the order. Three things go wrong:

• Unpadded numbers. Pages called 1.jpg to 24.jpg sort as 1, 10, 11… 19, 2, 20 in a plain alphabetical sort. Some readers sort naturally and get it right; others do not. Renaming to 001.jpg, 002.jpg works everywhere. Batch-renaming tools on every platform can do this in one pass.
• Covers that sort last. A cover called cover.jpg sorts after 001.jpg. Rename it 000.jpg or 000-cover.jpg.
• Badly nested folders. One folder inside the archive holding the pages is fine. Folders inside folders, or pages split across several folders, can produce a jumbled order or missing pages. Compress the images themselves, not the folder above the folder above them.

Keep ComicInfo.xml

If the CBR contained a ComicInfo.xml, put it in the new CBZ at the same level as the pages. It holds the series, issue number, writer, publisher and summary, and it is what lets a reader or a comic server group the issue with the rest of its series. Leave it out and the comic falls back to whatever can be guessed from its filename. ComicInfo.xml explained covers what is in it.

CB7 and CBA files

The same extract-and-re-zip method converts any comic archive. A CB7 is a 7-Zip archive; TritonPanels 2.0 opens CB7 directly, so you don’t need to convert for it, but some other readers and servers still don’t, and converting is harmless. A CBA is an ACE archive, an old format that few tools still extract. If you can find an archiver that opens it, convert it to CBZ while you still can.

The guides that sit next to this one are Open CBZ and CBR files and Make a CBZ file.

Frequently asked questions

Does converting CBR to CBZ reduce image quality?

No. The images are extracted and stored again exactly as they were; nothing is re-encoded. The CBZ shows the same pages at the same quality.

How do I know if a CBR is RAR5?

The file name will not tell you. Most desktop archivers show the archive format in their file properties or information view. In practice, if a CBR opens on your computer but not in a phone reader, RAR5 is the likely reason, and converting to CBZ fixes it either way.

Can I just rename .cbr to .cbz?

Only if the file was really a ZIP all along, which does happen. A genuine RAR archive stays RAR when renamed. TritonPanels checks the contents rather than the extension, so a misnamed ZIP opens in it whatever it is called.

Can I convert a CBR on my phone?

It is possible with an archiver app that can both extract RAR and create ZIP, but it is fiddly with hundreds of images and easy to get the page order wrong. A computer is much quicker, and you can then send the CBZ to your phone over Wi-Fi.

Your own files: TritonPanels reads comics you already have. It does not sell, host or supply comics, and it cannot open copy-protected (DRM) purchases that are locked to another store’s app. Komga, Kavita, Calibre, Dropbox and the other names on this page belong to their owners, who do not endorse TritonPanels.