Compress CBZ comics.
Comic archives slimmed page by page — all on your device.
Drop CBZ comics here
or browse your files
Paste with ⌘V · or drop files anywhere on the page
Files never leave your device. Everything runs in your browser, nothing touches a server — tools you've used even work offline.
Compress CBZ comic archives entirely in your browser — every page re-encoded in its own format at the quality you pick, with an optional downscale for e-readers. Filenames, page order and metadata stay exactly as they were. Nothing is uploaded.
How it works
- Drop files anywhere on the page, click to browse, or paste with ⌘V.
- Pick a quality or preset — or set an exact target size and let the tool find it.
- Compress, compare before/after, and download — individually or as a ZIP.
Comics are the perfect target
A CBZ is just a ZIP of page images, and scans are usually saved far larger than any screen can show — high resolutions, generous quality settings. Re-encoding at a sensible quality halves many archives outright, and the Max image size cap (1600 px covers tablets and e-readers comfortably) multiplies the savings on oversized scans. Pages that would grow are kept untouched, and page filenames never change, so reading order is exactly preserved.
Formats and edge cases, honestly
JPEG pages stay JPEG, PNG stays PNG (with transparency), WebP stays WebP; GIFs and ComicInfo.xml pass through untouched. Mislabeled archives are handled too — a "CBZ" that is really a RAR is read all the same. For actual .cbr files, CBR to CBZ does the container conversion; at quality 100 this tool is a lossless repack that only restructures the archive.
Frequently asked questions
Does the page order survive?
Yes — readers order pages by filename and every filename is preserved exactly, along with ComicInfo.xml metadata. Only the image bytes inside get lighter.
What quality should I pick?
The default (80) is visually transparent for most scans. For archival copies use 100 — pages that cannot shrink losslessly are simply kept, so nothing degrades.
Can I shrink pages for an e-reader?
Yes — set Max image size to 1600 px (or 1200 for small readers) and oversized scans are downscaled to fit, which is where the biggest savings usually come from.
Is it private?
Yes. Archives are built and converted entirely in your browser — neither the archive nor the files inside it are ever uploaded, and any password you set is applied locally. The server does nothing but deliver this page. Want proof? Run one file through, switch your connection off, and run another — it still works.