PBM to SIXEL Converter
FileFlip converts PBM to SIXEL 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 SIXEL?#
- 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 SIXEL 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 SIXEL file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting PBM to SIXEL lose quality?#
No. Converting PBM to SIXEL 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 SIXEL actually does to the file#
Converting PBM to SIXEL 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 → SIXEL |
| 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 |
Worth knowing before you start:
- the target holds at most 256 colours, so a full-colour image is quantised to a palette
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 SIXEL file?#
A SIXEL file holds a bitmap encoded entirely as printable ASCII characters, using DEC's six-pixel-tall encoding scheme, so it can be sent to a printer or terminal over a plain 7-bit serial link and displayed without any separate image protocol.
Use Sixel when an image needs to display inline inside a terminal session, such as showing a chart or a thumbnail over SSH without opening a separate viewer.
Convert a Sixel image to PNG once it needs to be viewed anywhere outside a terminal emulator that understands the encoding.
PBM to SIXEL 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.
What is a SIXEL file?
A SIXEL file is a bitmap image encoded as printable ASCII text using DEC's six-pixel-tall scheme, originally built in the early 1980s so DEC printers and terminals could receive graphics over the same serial link used for plain text.