.cb7 File Extension

What kind of file is a .cb7?

A .cb7 file is a digital comic packaged in a 7z archive. Its members are usually JPEG or PNG page images named in reading order. Some archives also include ComicInfo.xml metadata. The suffix tells comic-reading software to present those images as sequential pages instead of as an ordinary archive.

The commonly used application/x-cb7 MIME type is not registered with IANA. The freedesktop.org shared MIME database associates it with .cb7 and treats it as a subtype of application/x-7z-compressed.¹

A normal 7z file begins with the six bytes 37 7A BC AF 27 1C.² That signature confirms the container, not the comic intent. Check that the archive contains a sensible image sequence before trusting a misleading filename.

How do I open a .cb7 on my computer?

• On Windows and macOS, calibre can import, read, and convert CB7 files.³
• On Linux, calibre works across common desktop environments. Okular also supports CB7 through its comic-book reader.⁴
• With 7-Zip or another 7z utility, you can inspect and extract the original page images, but you will not get comic-reader controls such as page spreads or reading direction.

If pages appear as 1, 10, 2, rebuild the archive with zero-padded names such as 001, 002, and 010. Readers can disagree about sorting because CB7 has no published normative specification.

Poly support for .cb7

Poly gives supported CB7 comics a thumbnail and paginated preview, then makes page text and visual content searchable. OCR helps with words drawn into scanned pages, and the Poly agent can read page text and images together.

The preview is a converted document view, so keep the original when exact image bytes, archive properties, or native comic metadata matter. Encrypted, damaged, or unsupported archives may have limited processing.

History of .cb7

CB7 has no authoritative inventor or introduction date. It developed as part of the comic-book archive family, where the final letter indicates the underlying container: CBZ uses ZIP, CBR uses RAR, CBT uses TAR, and CB7 uses 7z.

Desktop and reader support emerged independently rather than through a formal standard. Okular 1.9 added CB7 support in December 2019, while current calibre documentation lists CB7 among its supported input formats.³⁴

Working with .cb7 and alternatives

Choose CBZ when device compatibility matters most, PDF for fixed pages and printing, or extracted images for editing and restoration. Conversion requires extracting or decoding the CB7 and writing a new output format. It is not a filename-only change.

Treat unknown CB7 files as untrusted archives. Inspect their members with maintained software, reject paths that escape the extraction folder, and avoid unexpected executables. 7z can use solid compression and AES-256 encryption, but encryption does not prove who created a file or whether its contents are safe.⁵