PBM to RAS Converter
FileFlip converts PBM to RAS 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 PBM file to RAS?#
- Drop your PBM 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 RAS 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 RAS file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting PBM to RAS lose quality?#
No. Converting PBM to RAS writes the data out again without discarding any of it, so nothing that was in the PBM file is lost on the way. What changes is the size of the file, not what is inside it.
Is it safe to convert PBM files online?#
Yes, because nothing is uploaded. FileFlip converts PBM 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 PBM to RAS actually does to the file#
Converting PBM to RAS 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.
| Engine | ImageMagick |
|---|---|
| Conversion path | One step: PBM → RAS |
| 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 is a PBM file?#
A PBM file stores a strictly black-and-white, one-bit-per-pixel raster image as plain ASCII characters or packed binary bits, in the Netpbm project's Portable Bitmap format.
Use PBM for a strictly black-and-white bitmap, such as a fax page or a stencil mask, that needs to move between tools without any image library.
Convert PBM to PNG once the image needs compression or has to sit alongside greyscale or colour images in the same pipeline.
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.
PBM to RAS questions people ask#
What does PBM stand for?
PBM stands for Portable Bitmap, the black-and-white member of the Netpbm family of image formats that Jef Poskanzer created to move images between Unix tools. It is the strictly one-bit sibling of the colour PPM and greyscale PGM formats.
Is a 1 a black pixel or a white pixel in a PBM file?
In a PBM file, a 1 represents a black pixel and a 0 represents a white pixel, which is the opposite of what many people expect from a plain greyscale scale. This is defined directly in the Netpbm project's own PBM specification.
Why is my PBM file bigger than a similar PNG?
A PBM file stores one bit per pixel with no compression at all, while PNG compresses that same data losslessly, so a large black-and-white image can end up many times smaller as a PNG. PBM trades file size for a format simple enough to read and write without any image library.
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.