Free online BDF to WOFF2 converter

What the BDF format is

BDF, or Bitmap Distribution Format, is a plain-text font format that stores glyphs as grids of on/off pixels together with metrics such as encoding, width, height, and bearings. It is used mainly for low-resolution screen fonts, terminal fonts, embedded systems, and X Window System font collections.

Bitmap-font tools and font editors such as FontForge can create or export BDF files. You may also encounter BDF files in source packages for specialist technical fonts, console fonts, and fonts designed for fixed-size display rather than scalable page layout.

What the WOFF2 format is

WOFF2 is a compressed wrapper for webfont data based on OpenType or TrueType tables. Browsers load it with CSS using @font-face, and its Brotli-based compression normally makes it smaller than WOFF or an uncompressed TTF file.

WOFF2 is intended for scalable outline fonts. A BDF contains bitmap glyphs, so a conversion can produce a WOFF2 file that retains bitmap strikes, or it can first turn the pixels into vector outlines. The second option is generally more usable at arbitrary web sizes, but it does not recreate the original glyphs exactly.

How to actually convert BDF to WOFF2

FontForge is the practical desktop option because it can open BDF files, inspect their glyphs, and generate webfont formats.

1. Install a FontForge build with WOFF2 generation support.
2. Open the file through File → Open and select the .bdf file.
3. Check the encoding, glyph names, em size, ascent, descent, and character metrics. Correct missing or incorrectly encoded glyphs before export.
4. If the source is bitmap-only and the target must scale cleanly, select the relevant glyphs and use FontForge's bitmap-to-outline tracing tools. Inspect the resulting outlines at several sizes; tracing can add jagged contours or excessive points.
5. Choose File → Generate Fonts, select WOFF2 as the output format, specify a filename such as font.woff2, and generate the file.
6. Test the result in a browser with a CSS declaration such as @font-face { font-family: BdfConverted; src: url("font.woff2") format("woff2"); }.

FontForge can also be used from a shell when the installed build supports WOFF2 output:

fontforge -lang=ff -c 'Open($1); Generate($2)' input.bdf output.woff2

For a conversion without installing software, upload the BDF file to the free converter on 101convert.com, select WOFF2, and download the generated file. Verify the glyphs and metadata before using it in production.

Quality, compatibility, and limitations

WOFF2 compression does not improve bitmap resolution. If bitmap strikes are preserved, the font may render only at its supplied pixel sizes or may have limited support in browser text engines. Converting pixels to outlines makes scaling possible but changes the appearance and can lose deliberate pixel-grid design.

Check Unicode mappings after conversion, especially for fonts containing private-use characters or nonstandard encodings. Test Latin, accented characters, symbols, and any application-specific glyphs rather than checking only the basic alphabet.

Also verify the BDF font's license before distributing a WOFF2 derivative. A webfont exposes its glyph data for download, and the license may restrict modification, redistribution, or web embedding.