CBZ vs CBR vs CB7: Which Format Should You Use?
They all open the same way in your reader. But CBZ, CBR, and CB7 are fundamentally different archive formats — and knowing the difference matters for long-term collection management, metadata embedding, and compatibility.
What are comic book archive formats?
CBZ, CBR, and CB7 are all the same idea: a folder of images — one per page — compressed into a single file and renamed with a comic-specific extension. Open one in any reader and you'd never know the difference. But under the hood they use different compression formats, and that matters for metadata, compatibility, and how well library apps handle them.
The three main formats
CBZ is the best format for long-term storage and compatibility. ZIP is an open standard — no proprietary compression, no licensing issues, and every operating system can open it natively without extra tools.
More importantly, ComicInfo.xml can be embedded inside a CBZ without breaking anything. This is the metadata standard used by Kavita, Komga, YACReader, and Torika. Drop a ComicInfo.xml into the ZIP and your app reads series name, volume number, author, and genre without having to guess from the filename.
If you're building a collection from scratch or converting your existing files, CBZ is the right choice.
CBR uses the RAR compression format, which is proprietary to RARLab. Creating RAR files requires a paid license (WinRAR). Reading them is free — which is why most readers support CBR — but there's no reason to create new CBR files in 2026.
CBR is extremely common in older scanlation releases, so you'll encounter a lot of it. It works fine for reading. The main downside: ComicInfo.xml metadata embedded in a RAR is less reliably read by all apps, and manipulating RAR archives on Mac requires third-party tools.
CB7 uses 7-Zip compression, which achieves better compression ratios than ZIP or RAR — typically 10–30% smaller files for the same image quality. If you're archiving a very large collection and storage is a constraint, CB7 can make a real difference.
The tradeoffs: 7-Zip extraction is slower (noticeable on page turns with large files), and not every reader supports CB7. It's supported by Kavita, Komga, Torika, and YACReader — but check before committing your whole collection to it. ComicInfo.xml works inside CB7 the same as CBZ.
Which format does your collection actually have?
The honest answer for most collectors: a mix of everything. Older scanlations are almost always CBR. Newer groups and official digital rips increasingly use CBZ. CB7 shows up occasionally for high-quality archival releases.
All three read identically in any app that supports them. The difference is mostly relevant when you want to:
- Embed ComicInfo.xml metadata reliably → prefer CBZ
- Minimise storage use → CB7 for archival, CBZ otherwise
- Maximise compatibility across apps and devices → CBZ
What about PDF?
PDFs are a separate case. They're not archive formats — they're document formats that may contain rasterised images, vector art, or both. They're common for official digital releases and light novels.
Most manga readers handle PDFs, but they're slower to open than CBZ/CBR and don't support ComicInfo.xml. For a collection that's mostly manga, PDFs are best treated as a read-only format — keep them as-is and let your library app handle the metadata.
The short version
- CBZ — use this. Open standard, best compatibility, works with ComicInfo.xml.
- CBR — keep existing files as-is, don't create new ones.
- CB7 — good choice if storage matters and your app supports it.
- PDF — fine for reading, not ideal for collection management.
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