What Is a PBM File?

This article explains what a PBM file is, how it's different from other image formats, and how to open or convert one to a different file format like PDF, JPG, and others.

What Is a PBM File?

A file with the PBM file extension is a Portable Bitmap Image file.

This isn't nearly as common a format as PNG, JPG, GIF, and others you've probably heard of. One big difference is that these are text-based, black and white images that contain either a 1 for a black pixel or a 0 for a white pixel.

How to Open a PBM File

PBM files can be opened with Inkscape, XnView, Adobe Photoshop, Netpbm, ACD Systems Canvas X Draw, Corel PaintShop Pro, and probably several other photo and graphics tools as well.

Given that they are text files and contain mainly just ones and zeros, you can also use any text editor, like Notepad++, Notepad in Windows, or a text editor from this list, to open it. We have an example of a very basic PBM file below.

How to Convert a PBM File

The easiest way to convert PBM to PNG, JPG, BMP, or some other image format is to use a free file converter. Two of our favorites are the online converters FileZigZag and Convertio.

Another conversion method is to open it in one of the viewers/editors mentioned above, like Inkscape, and then save it to PDF, SVG, etc.

Example of a PBM File

When you open a PBM file in a text editor, it looks to be nothing but text—maybe a few codes and some notes, but certainly lots of 1s and 0s.

Here's a very simple example of a PBM image that would, when viewed as an image, look like the letter J:

P1
# The letter "J"
6 10
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
1 0 0 0 1 0
0 1 1 1 0 0
0 0 0 0 0 0
0 0 0 0 0 0

If you look closely, assuming the page you're reading right now isn't breaking up the numbers you see above, you can actually see the 'J' represented as 1s.

Most image files don't work anywhere near this way, but PBM files do and are certainly an interesting way to create images.

More Information on the PBM File Format

PBM files are used by the Netpbm project and are similar to the Portable Pixmap Format (PPM) and the Portable Graymap Format (.PGM) format. Collectively, these file formats are sometimes called the Portable Anymap Format (.PNM).

Portable Arbitrary Map (.PAM) is an extension of these formats.

You can read more about the Netpbm format on Netbpm and Wikipedia.

Still Can't Open It?

Some file formats use a file extension that looks similar to .PBM, but that doesn't mean they actually have anything in common. If your file doesn't open with the programs mentioned above, it probably means you're not dealing with a PBM file; in other words, you'll need to look elsewhere for a way to open it.

A few good examples of how easy it can be to mix up file extensions can be seen when you consider these: PBP (PSP Firmware Update), PBN (Portable Bridge Notation), PDB, and PBD (EaseUS Todo Backup). Each extension belongs to a separate format, so each of those files need a different program to open/edit/convert it.