Free · Private · In your browser
CBR to CBZ Converter
Convert RAR-based comic archives to the open CBZ format every reader supports.
Files never uploaded Works offline Free, no signup No file size limits
How it works
- Drop your CBR file (several at once is fine).
- The RAR archive is unpacked in your browser and the pages are repacked as a standard zip.
- Download a CBZ that any comic reader on any platform opens.
Why “no upload” matters
Every conventional converter site works the same way: your file travels to their server, sits in their queue, gets converted on their hardware, and – you hope – gets deleted afterwards. You can’t verify any of it. The FBI has even warned about free converter sites that use that upload as a way to deliver malware or harvest the documents themselves. And with comics, uploading is not just a trust problem – at a gigabyte per volume it’s a bandwidth problem too.
ebook.tools removes the question entirely. The converter is delivered to your browser as code and runs on your machine; the file you drop is opened from memory, transformed, and saved back – the network isn’t involved at all. That isn’t a policy promise, it’s an architecture, and you can test it: load this page, switch off your wifi, and convert. It works exactly the same, because there was never anything to send.
Why CBR is a dead end, and why the fix is lossless
CBR and CBZ hold exactly the same thing – a folder of page images – but they differ in one detail that matters more every year: CBR uses RAR compression, and RAR is proprietary. Its decompression code can't be freely embedded, so open-source comic readers either ship awkward workarounds or skip CBR entirely. That's why your CBR collection opens fine in one app, shows empty pages in another, and isn't recognised at all on your new tablet. CBZ is plain zip: patent-free, implemented everywhere, readable by every comic app on every platform – and by any unzip tool, which is what makes it the archival-safe choice.
The good news is that converting between them is the rare conversion with zero quality cost. Your page images are not touched: not re-encoded, not resized, not recompressed. The converter unpacks the RAR container, takes the identical image bytes, and packs them into a zip. What comes out is pixel-for-pixel, byte-for-byte the same artwork in a container that will still open in twenty years.
Because comics are huge and this site uploads nothing, the repack is also fast – a 500MB volume converts in seconds on an ordinary machine, limited by your disk rather than your upstream bandwidth. Batch is natural too: drop a whole stack of CBRs and each is repacked in turn.
One niche caveat: a small number of very old CBR files use RAR features (like solid archives with unusual settings) that browsers struggle with; those are rare, and you'll get a clear error rather than a corrupted file. Once you're in CBZ-land, our CBZ to PDF tool takes you the rest of the way to a format that opens on anything with a screen.