bdf

.bdf — Bitmap Distribution Format

Apple Inc. · 1990

Developer
Apple Inc.
Category
Fonts
MIME Type
application/font-sfnt
First Released
1990
Open Format
No
File Signature
No standard header signature; identified by file content and structure.
At a Glance
.bdf
Bitmap Distribution Format

BDF is a text-based font file format primarily used for storing bitmap representations of characters.

Reviewed on August 1, 2026
Compression
Plain text
Transparency
N/A
Editability
High
Best for
Bitmap font data

Key Features

  • Text-based format for easy inspection and editing.
  • Stores fonts as bitmap images for each character.
  • Supports basic font metrics and metadata.
  • Primarily used in older computing environments.

Best For

  • Creating simple, fixed-size bitmap fonts for specific applications.
  • Manual font data inspection and modification in a text editor.
  • Ensuring compatibility with very old or specialized systems that require bitmap fonts.

Less Ideal For

  • Modern operating system font rendering, which requires scalable vector fonts.
  • Web design, where performance and scalability are critical.
  • High-quality print documents needing sharp text at various sizes.
  • Applications requiring advanced typographic features like ligatures or kerning.

Common Use Cases

  • Displaying fixed-size characters in legacy graphical interfaces.
  • Font data storage for early X Window System applications.
  • Manual editing or creation of simple bitmap fonts.
  • Archiving or representing fonts from older systems.

How to Open It

  1. Open with a plain text editor (like Notepad, VS Code, Sublime Text) to view or edit the raw data.
  2. Use font management tools or graphics software that specifically supports the BDF format for import.
  3. Convert BDF files to more modern formats using specialized font conversion utilities if needed for broader compatibility.

What is a .bdf file?

The Bitmap Distribution Format (BDF) is an older, text-based file format for storing font data. It's designed to represent fonts as collections of bitmaps, where each character is a grid of pixels. While it was useful in early graphical systems, modern operating systems and applications generally prefer more advanced vector-based font formats like TrueType or OpenType. BDF files are relatively easy to read and edit manually due to their plain text structure, but this also makes them larger and less efficient than binary formats. Therefore, they are rarely used for general-purpose font distribution today.

Programs That Open .bdf Files

PlatformProgram
WindowsNotepad++Free
FontForgeFree
macOSTextEditFreeOfficial
FontForgeFree
LinuxgeditFreeOfficial
FontForgeFree

How to Convert .bdf Files

FormatMethod
.TTFFontForge, Online Converters
.PNGFontForge, Specialized Scripts

Common Problems with .bdf Files

⚠️ BDF fonts are not scalable and appear pixelated when enlarged.
Use vector-based font formats like TTF or OTF for applications requiring scalable text.
⚠️ Limited character support and typographic features compared to modern fonts.
For advanced typography, use formats like OpenType (OTF).
⚠️ BDF files can be large due to storing full bitmaps for each character.
Consider compressed vector formats like WOFF2 for web use or efficient storage.

Frequently Asked Questions

What is the main advantage of the BDF format?▼

Its primary advantage is its human-readable, text-based structure, making it easy to inspect and manually edit, which was useful in early graphical systems.

Can BDF fonts be used on modern operating systems?▼

While some older systems or specialized software might support them, modern OSes prefer and perform better with scalable vector font formats like TrueType (TTF) or OpenType (OTF).

Is BDF suitable for high-resolution displays?▼

No, BDF is a bitmap format and will appear pixelated and lose quality when scaled to high resolutions or larger sizes.

Technical Details

BDF files are plain text files with a specific structure that defines font properties, metrics, and bitmap data for each character. The format supports monochrome (black and white) bitmaps and includes metadata for character spacing, ascent, descent, and bounding boxes. Due to its bitmap nature, it does not scale smoothly like vector fonts and is typically associated with older X Window System environments.

Did You Know?

BDF stands for Bitmap Distribution Format, highlighting its nature of storing fonts as pixel grids.
It was developed by Apple Computer and commonly used with the X Window System in Unix-like operating systems.

Security Information

BDF files themselves are generally considered safe as they contain font data. However, as with any file, exercise caution when downloading from untrusted sources, as malicious code could theoretically be embedded in applications that process BDF files, though this is uncommon for the format itself.