PFB is a file extension that stands for Printer Font Binary. It keeps the basic ones and zeroes that tell programs how to write letters and numbers. The file type belongs to an old category called Type 1 fonts. Newer file types for fonts have since emerged, making PFB files functionally obsolete. Engineers might encounter PFB files on AutoCAD, and artists might see them on CorelDRAW or Adobe PhotoShop. Otherwise, this file type is rare to see. If you want to open a PFB file, the free FontForge software can do so on Windows, macOS, and Linux devices. PFB files are not typically dangerous to look at or open. Exceptions always exist, so exercise normal precautions before opening an unknown PFB file, including an antivirus scan.