CBZ to SUN Converter
FileFlip converts CBZ to SUN entirely inside your browser, using MuPDF and ImageMagick compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a CBZ file to SUN?#
- Drop your CBZ file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to SUN and the conversion starts on its own. FileFlip downloads 24.1 MB of WebAssembly the first time and nothing after that, then runs MuPDF and ImageMagick on your own machine.
- Save the SUN file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting CBZ to SUN lose quality?#
Yes, in the sense that text stops being text. Each CBZ page is rendered to pixels and handed to SUN, so the result looks right and can no longer be selected, searched, or reflowed.
Is it safe to convert CBZ files online?#
Yes, because nothing is uploaded. FileFlip converts CBZ files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What CBZ to SUN actually does to the file#
Converting CBZ to SUN runs on MuPDF and ImageMagick, downloads 24.1 MB of WebAssembly the first time and nothing after that, renders each page to pixels, keeps page layout, and drops selectable text and transparency.
| Engine | MuPDF and ImageMagick |
|---|---|
| Conversion path | 2 steps: CBZ → PNG → SUN |
| Downloaded to your browser | 24.1 MB, once, then cached by your browser |
| Quality | Text becomes pixels |
| You get back | One image per page, zipped when the source has several |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Selectable text | Dropped | The target format has nowhere to put it. |
| Page layout | Kept | Carried through into the converted file. |
| Transparency | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- pages render at twice their point size in opaque RGB, roughly 144 DPI, with no transparency
What is a CBZ file?#
A CBZ file is a ZIP archive of page images, usually JPEG or PNG, named so they sort into reading order, with nothing else defining it as a comic beyond that convention.
Use CBZ to distribute a scanned or digital comic as sequential page images that any comic reader opens without conversion.
Convert CBZ to PDF when a comic needs to move into software that expects a page-based document instead of a folder of images.
What is a SUN file?#
A SUN file is a Sun Raster bitmap, the same raw framebuffer image format Sun Microsystems shipped on SunOS workstations, saved under the alternate .sun extension some raster-image tools use in place of the identical .ras.
Recognise a .sun file as a Sun Raster image if it turns up alongside .ras files from the same legacy Solaris export or archive.
Convert SUN to PNG or TIFF for any modern use, since the .sun extension gets even less software recognition than .ras.
CBZ to SUN questions people ask#
What is a CBZ file?
A CBZ file is a ZIP archive holding a comic's pages as individual image files, named so they sort into the right reading order. There is no page-layout data or text encoding involved, which is the entire format: a comic reader just opens the ZIP and displays the images in sequence.
What's the difference between CBZ and CBR?
CBZ and CBR hold the same kind of content, sequential page images, but CBZ is a renamed ZIP archive while CBR is a renamed RAR archive. Most comic readers open both, but ZIP's open format makes CBZ the more portable of the two.
Can a CBZ file store metadata like the comic's title or issue number?
Yes, many CBZ files include a ComicInfo.xml file inside the archive alongside the page images, which readers like Calibre and CDisplayEx use to show series, issue number and creator credits. It is optional, so a CBZ file without one has no metadata beyond the page images themselves.
What is a SUN file?
A SUN file is a Sun Raster bitmap, the simple framebuffer image format Sun Microsystems used on SunOS and Solaris workstations, identified by a fixed magic number at the start of the file rather than by its extension.