SUN to AVIF Converter
FileFlip converts SUN to AVIF 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 AVIF?#
- 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 AVIF 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 AVIF file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting SUN to AVIF lose quality?#
Yes, once. SUN keeps everything and AVIF 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 AVIF 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 AVIF actually does to the file#
Converting SUN to AVIF 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 → AVIF |
| 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 an AVIF file?#
An AVIF file holds a still image or short animation encoded with the AV1 video codec, packaged inside a HEIF-style container that also carries HDR and wide-colour-gamut data alongside the pixels.
Use AVIF for web images where file size matters most, since it now decodes natively in every major browser and beats JPEG and WebP on compression at the same quality.
Convert AVIF to JPEG or PNG when a file is headed somewhere that still rejects it, such as an older content management system, a print workflow, or an app without AV1 decoding.
SUN to AVIF 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 an AVIF file?
An AVIF file is an image compressed with the AV1 video codec instead of the older JPEG or WebP algorithms, which is why it produces noticeably smaller files at the same visual quality. It was created by the Alliance for Open Media, the same group behind the AV1 video format, and first shipped in 2019.