PNG to SUN Converter
FileFlip converts PNG to SUN 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 PNG file to SUN?#
- Drop your PNG 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 14.1 MB of WebAssembly the first time and nothing after that, then runs 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 PNG to SUN lose quality?#
No. Converting PNG to SUN writes the data out again without discarding any of it, so nothing that was in the PNG file is lost on the way. What changes is the size of the file, not what is inside it.
Is it safe to convert PNG files online?#
Yes, because nothing is uploaded. FileFlip converts PNG 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 PNG to SUN actually does to the file#
Converting PNG to SUN runs on ImageMagick, downloads 14.1 MB of WebAssembly the first time and nothing after that, writes the data out again without discarding any of it, and drops EXIF metadata, ICC colour profile and transparency.
| Engine | ImageMagick |
|---|---|
| Conversion path | One step: PNG → SUN |
| Downloaded to your browser | 14.1 MB, once, then cached by your browser |
| Quality | Lossless |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| EXIF metadata | Dropped | The target format has nowhere to put it. |
| ICC colour profile | Dropped | The target format has nowhere to put it. |
| Transparency | Dropped | The target format has nowhere to put it. |
What is a PNG file?#
A PNG file stores a raster image using lossless DEFLATE compression, which is why screenshots, logos, and graphics with flat colour or sharp edges use it instead of JPEG.
Use PNG for screenshots, logos, icons, and any graphic with flat colour or transparency, where exact pixel reproduction matters more than file size.
Convert PNG to JPEG or WebP when the image is a photograph and file size matters more than pixel-perfect reproduction, since a photographic PNG is typically several times larger than an equally sharp lossy file.
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.
PNG to SUN questions people ask#
Is PNG lossless?
Yes, PNG is always lossless. It compresses image data with the DEFLATE algorithm, the same family of compression used in ZIP files, so every pixel decodes back exactly as it was encoded. There is no lossy PNG mode, unlike JPEG.
Does PNG support animation?
A standard PNG file does not animate; it holds exactly one image. Animated PNG (APNG) is a separate extension, created by Mozilla developers in 2008 and folded into the official PNG specification in 2025, that stores multiple frames inside a file that still uses the .png extension. All major browsers now play APNG frames, but many image editors and older viewers only show its first frame, so GIF or WebP remain more reliable choices when animation has to work everywhere.
Why is my PNG file so much bigger than the same photo saved as JPEG?
PNG's DEFLATE compression is lossless, so it has to encode every bit of the noise and subtle colour variation a photograph contains. JPEG gets its smaller size by discarding detail the eye barely notices, which a lossless format like PNG can't do. PNG stays efficient for flat-colour graphics like screenshots or logos; it's photographs where the size difference shows up.
Does PNG support transparency?
Yes, PNG supports transparency through an alpha channel, letting each pixel be fully opaque, fully transparent, or partially see-through. It works on both truecolour and palette-based PNGs, which is why PNG is the standard choice for logos and icons that need to sit on any background.