SUN to PJPEG Converter
FileFlip converts SUN to PJPEG entirely inside your browser, using 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 SUN file to PJPEG?#
- Drop your SUN 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 PJPEG and the conversion starts on its own. FileFlip downloads 14.1 MB of WebAssembly the first time and nothing after that, then runs ImageMagick on your own machine.
- Save the PJPEG file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting SUN to PJPEG lose quality?#
Yes, once. SUN keeps everything and PJPEG does not, so this is the first time the file meets a lossy encoder. At high quality the difference is hard to see, and it is worth keeping the SUN original, because every later re-save of the PJPEG loses a little more.
Is it safe to convert SUN files online?#
Yes, because nothing is uploaded. FileFlip converts SUN 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 SUN to PJPEG actually does to the file#
Converting SUN to PJPEG runs on ImageMagick, downloads 14.1 MB of WebAssembly the first time and nothing after that, encodes a lossless source with a lossy encoder for the first time.
| Engine | ImageMagick |
|---|---|
| Conversion path | One step: SUN → PJPEG |
| Downloaded to your browser | 14.1 MB, once, then cached by your browser |
| Quality | Lossy, first generation |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
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.
What is a PJPEG file?#
PJPEG is progressive JPEG, a JPEG encoding choice rather than a different file format, where the image is built up through several increasingly detailed scans across the whole picture instead of filling in top to bottom in one pass.
Choose progressive encoding for images shown over a slow or uncertain connection, where a quick blurry preview beats a slow top-down reveal.
Convert to baseline JPEG when a downstream tool or embedded device only supports the simpler sequential scan order.
SUN to PJPEG questions people ask#
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.
Is SUN the same format as RAS?
Yes, a SUN file and a RAS file are the identical Sun Raster format. The two extensions exist because different tools over the years registered the format under different names, not because the files differ in any way.
Can I just rename a .sun file to .ras?
Renaming a .sun file to .ras works, because the two extensions point at the same byte-for-byte format and most decoders identify a Sun Raster file by its magic number rather than its extension. Some tools that only recognise .ras will open the renamed file without issue.
What is PJPEG?
PJPEG is progressive JPEG, a JPEG file encoded in a handful of increasingly detailed scans instead of one pass from top to bottom. It's still a JPEG file, just encoded differently, and opens anywhere JPEG does.