BDF (bitmap font)
Also known as: .bdf file, Glyph Bitmap Distribution Format, X11 BDF
BDF (Glyph Bitmap Distribution Format) is a text-based bitmap font format from the X Window System. Each character is described as a grid of pixels in plain text, making it readable, editable, and easy to convert.
- Text-based bitmap font from the X Window System
- Each glyph is a fixed-size pixel grid
- Still used for embedded and pixel displays
How BDF works
A BDF file lists each glyph as hexadecimal rows of pixels along with its size and position, all in human-readable text. Because the glyphs are bitmaps, a BDF is tied to a specific pixel size.
It was a standard way to distribute screen and terminal fonts on Unix systems and remains popular for pixel-perfect and embedded displays.
BDF today
BDF is still used where exact pixel control matters, like small LCDs and retro interfaces. For scalable type, convert to TTF or OTF, or compile BDF into the binary PCF that X used at runtime.