What is a .cb7 file?
Comic Book 7z Archive · eBook · Comic reader community · 2000s
A .cb7 file is a comic book archive using 7-Zip compression: a 7z archive of page images renamed so comic readers recognise it. The strong 7z compression makes for smaller files than CBZ.
What is a .cb7 file used for?
Rename a .cb7 to .7z and it extracts to numbered page images. Because 7z compresses harder than ZIP, CB7 files are smaller, at the cost of needing a 7z-capable reader.
Modern comic readers open CB7; otherwise extract with 7-Zip and view the images. Convert to CBZ for the widest compatibility.
What opens a .cb7 file?
The .cb7 format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- YACReader
- CDisplayEx
- 7-Zip (to extract)
macOS
- YACReader
- The Unarchiver
Linux
- YACReader
- MComix
- 7z
Open a .cb7 file step by step
- Confirm the file really is a .cb7. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with YACReader or CDisplayEx.
- On Mac, use YACReader or The Unarchiver.
- On Linux, try YACReader or MComix.
- Still stuck? Convert the .cb7 to cbz, which opens more widely.
Why can't I open my .cb7 file?
Almost always because no installed app understands CB7. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .cb7 at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .cb7 file
You can convert a .cb7 file to cbz, pdf using a conversion tool or the export menu of an app that opens it.
What is the .cb7 file signature (magic bytes)?
A .cb7 file starts with the hex bytes 37 7A BC AF 27 1C, which read as 7z¼¯'. in ASCII. Programs identify CB7 by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for CB7. For a full breakdown, see the 7Z file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 37 7A BC AF 27 1C | 0 | 7z¼¯'. | 7z magic (CB7 is a 7z archive) |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .cb7 file?
A .cb7 file is a comic book archive using 7-Zip compression: a 7z archive of page images renamed so comic readers recognise it. The strong 7z compression makes for smaller files than CBZ.
How do I open a .cb7 file?
Use a comic reader like YACReader, or rename it to .7z and extract the images with 7-Zip.
Why use CB7 instead of CBZ?
7z compresses more than ZIP, so CB7 files are smaller. The trade-off is that fewer readers support 7z than ZIP-based CBZ.
How do I convert CB7 to CBZ?
Extract the images (rename to .7z), then zip them and rename the archive to .cbz, or use a comic manager that converts directly.
Related formats
Sources
Details on this page were checked against authoritative references. How sources are ranked and what is deliberately left out is set out in the methodology.