WebP to RAS Converter
Convert WebP to RAS in your browser. WebP files usually come from websites, Chrome's Save image as, CDNs and Android apps; RAS is the better fit for legacy Sun and Unix software. You get a 24-bit run-length encoded Sun Raster image. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
WebP expected · other image formats also work
How to use WebP to RAS
- 1
Add your WebP files: drop them here, choose them, or paste from the clipboard.
- 2
Pick the colour that replaces transparent areas, since RAS has none.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .ras files one at a time or together as a ZIP.
Why use Aback Images for webp to ras
Where the RAS goes next
RAS opens in ImageMagick, GIMP, XnView, IrfanView and Netpbm.
RAS next to WebP
The RAS keeps the decoded pixels without lossy compression, so expect it to be larger than the WebP.
No new artefacts
WebP is already lossy, since it stores lossy VP8 coding or lossless VP8L; the RAS keeps the decoded pixels losslessly, so this step adds no compression damage of its own.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
WebP vs RAS
What changes from WebP to RAS
Encoding: the WebP uses lossy VP8 coding or lossless VP8L; RAS uses none or a byte-oriented run-length encoding (RT_BYTE_ENCODED), and the download is a 24-bit run-length encoded Sun Raster image.
Bit depth: 8 bits per channel in the WebP; RAS allows 1, 8, 24 or 32 bits per pixel, and the RAS written here has 24 bits per pixel.
Colour: RGB; lossy WebP stores colour at half resolution (4:2:0) in the WebP; RAS supports monochrome, a colour map, or RGB stored as BGR, written here as 8-bit sRGB.
Transparency: the WebP stores it as a separate alpha plane, available in lossy as well as lossless files; the RAS has none, so transparent areas are filled with the colour you choose.
Animation: ANMF frame chunks, each with its own delay and blending; the RAS holds one image, so only the first frame is converted.
Metadata: the WebP can carry EXIF, XMP and ICC chunks; RAS can carry only a 32-byte header with size, depth, type and colour map length, but nothing is copied across.
About WebP
WebP is Google's web image format. It supports lossy and lossless compression, transparency and animation, and is typically 25 to 35 percent smaller than JPEG at the same visual quality.
A WebP is a RIFF file: 'RIFF', a length, 'WEBP', then chunks. A simple lossy file is one VP8 chunk and a lossless one is VP8L; the extended VP8X header announces alpha, animation, ICC, EXIF or XMP chunks.
WebP files usually come from websites, Chrome's Save image as, CDNs and Android apps.
About RAS
Sun Raster is the bitmap format of Sun Microsystems' SunOS and Solaris workstations. It stores 1, 8, 24 or 32-bit pixels, optionally with a colour map and simple run-length compression.
A Sun Raster file starts with the magic number 59 A6 6A 95 and a 32-byte header (width, height, depth, data length, type, colour map type and length), then the colour map and the rows, each padded to an even number of bytes.
When converting WebP to RAS makes sense
RAS is the better choice for legacy Sun and Unix software, while WebP suits images on websites and in apps.
RAS strengths: Simple and well documented; Read by ImageMagick, GIMP and many viewers. Drawbacks to weigh: Obsolete outside old Unix systems; No transparency in practice; Weak compression.
Limitations
- WebP images saved from websites are often already resized and compressed for the page, so the result cannot be sharper than that copy.
- Sun Raster has no alpha channel, so transparency is flattened onto the background colour.
- Modern viewers such as IrfanView, XnView and GIMP still open it.
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Frequently asked questions
Does converting WebP to RAS lose quality?
RAS is written losslessly, so the pixels are stored exactly as decoded. Artefacts already in the WebP stay, but nothing new is lost.
What happens to transparency when converting WebP to RAS?
WebP stores transparency as a separate alpha plane, available in lossy as well as lossless files. RAS has no alpha channel, so transparent pixels are composited onto a solid colour, white unless you pick another. To keep transparency, convert to PNG, WebP or AVIF instead.
Will my animated WebP stay animated?
No. RAS holds a single image, so only the first frame is kept. Convert to animated WebP, APNG or GIF to keep the motion, or export every frame with the GIF Frame Extractor.
Which apps open RAS files?
ImageMagick, GIMP, XnView, IrfanView and Netpbm. It does not open in web browsers.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.