What is a digital comic file? (DRM, CBZ, CBR, etc)

Re-Updated on 2014-09-10

Comic books served digitally come in many different forms. These can be broken down into two categories of digital comics, those protected with digital rights management (DRM) and those without. The former can come in many shapes and sizes, where the most popular is those delivered by Comixology. These are typically not ‘files,’ but a proprietary viewer that allows the user to read the comics. The user does not ‘own’ the comics and the service is ‘allowing’ the user to read the comics they purchase. It works and it can work well, but you are at the mercy of the company you buy from since you do not ‘own’ them.

This is where comic files that are not DRM protected come in play. You can think of these types of files as any other you may have on your computer, such as a picture, word document, or PDF file. The files have no built-in protection and can be viewed by a variety of readers. There is no standard file format for comic files, but there is a de-facto standard.

You may see a variety of formats for DRM-unprotected comic files:

  • CBZ
  • CBR
  • CB7
  • CBT
  • CBA
  • CB and some other letter


What this represents in the file’s extension. For instance, you may see a comic file named “XMen 013.cbz”. This is X-Men issue #13 in the CBZ format. The good thing is that you don’t need to care. The ones that are bold are the ones you typically encounter and the vast majority of comic reader applications support both.

A comic file is merely a ‘zipping’ of a set of images. In this case, the ‘Z’ in CBZ indicates this uses zip compression, the most common method for file compression. If you want to learn how to create a comic file, read the earlier post.

Now, you say, how do I get DRM-free comic files? As of very recently, there are now several publishers that distribute their comics in CBZ format, such as Image Comics. You can also get an increasing number from digital publishers, such as Comixology (although they are not all available in CBZ!). Unfortunately, this does not include the top 2 publishers: DC and Marvel. This means that if you want to read comics not available in this format, you will need to create your own files (eg: scan the pages) or download them “some-how.”

Once you have located a comic file you want to read, you can grab a variety of readers, but I would suggest the reader linked to this blog, the Comic Seer readers.


Comic Seer for Windows 8.1 and Windows RT tablets

Comic Seer for Windows 8.1 and Windows RT tablets

Comic Seer for the Windows desktop and Linux

Comic Seer for the Windows desktop and Linux



You can use one of these reading applications to open the files directly. You can also synchronize your files between devices (desktop, laptop, tablet, phone) using typical cloud storage solutions, such as Dropbox or Microsoft’s OneDrive.

If you combine a comic reader with a cloud solution, you can can have a great experience across all of your devices without having to worry about where your files are. This can give you all of the benefits of a DRM-protected digital comic service with the freedom to use your files as you prefer.


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