RAS to AVIF Converter
FileFlip converts RAS 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 RAS file to AVIF?#
- Drop your RAS 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 RAS to AVIF lose quality?#
Yes, once. RAS 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 RAS original, because every later re-save of the AVIF loses a little more.
Is it safe to convert RAS files online?#
Yes, because nothing is uploaded. FileFlip converts RAS 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 RAS to AVIF actually does to the file#
Converting RAS 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: RAS → 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 RAS file?#
A RAS file is a Sun Raster bitmap, the raw framebuffer image format Sun Microsystems built into SunOS workstations, and it is byte-for-byte identical to the format most tools also recognise under the .sun extension.
Open a RAS file when it comes from legacy Sun or Solaris workstation software, or from an old dataset captured directly off a SunOS framebuffer.
Convert RAS to PNG or TIFF for anything beyond archival viewing, since almost no current software or web platform accepts Sun Raster natively.
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.
RAS to AVIF questions people ask#
Is a RAS file the same as a SUN file?
Yes. A RAS file and a SUN file are the same Sun Raster format, identified by the same magic number and header layout, just saved under two different extensions that various tools have used over the years.
What software still opens RAS files?
ImageMagick, GIMP and viewers like IrfanView and XnView still read RAS files, since Sun Raster support has stayed in their format libraries even though the format itself dates to 1980s Sun workstations. Most mainstream photo apps and web browsers do not.
Why is my RAS file so large?
Most RAS files store pixel data uncompressed, since Sun Raster's optional run-length encoding was only ever one of several supported modes rather than the default. Converting to PNG or TIFF typically shrinks the same image considerably.
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.