What to Check Before Using a Font from FOSSFonts

Updated

FOSSFonts describes itself as a curated list of free fonts that are "100% free to use" and suitable for commercial projects. That site-level claim is a good starting point, but it is not a substitute for checking the individual font. Before you download and ship a typeface from the collection, confirm four things: the exact license of that font, whether attribution is required, whether it covers the characters and languages you need, and whether the file format works in your software.

Start with the font's own license, not the site banner

FOSSFonts presents itself as a curated list of free and open source fonts for commercial use. Curation reduces risk, but licenses are attached to fonts, not to directories. Two fonts on the same page can carry different terms.

What to look for

  • License name and version. Open source font licenses such as the SIL Open Font License (OFL) and the Apache License are common, but each has its own conditions. Note which one applies to the font you picked.
  • The license text or link. Look for a LICENSE or OFL.txt file in the download, or a license field on the font's listing or its upstream project page.
  • Reserved Font Name clauses. Some OFL fonts declare a Reserved Font Name, which restricts distributing modified versions under the original name. This matters if you plan to edit or subset the font.
  • Version drift. If the listing links to an upstream repository, check whether the license changed since the copy you are downloading.

If a listing gives no license information and no link to the source project, treat that as a gap to resolve before use, not as permission.

Check whether attribution is required

"Free" and "no strings" are not the same thing. Some licenses require you to credit the author, include the license text, or both.

  • OFL fonts generally require that the copyright notice and license travel with the font, and that you not sell the font by itself.
  • Apache-licensed fonts typically require preserving notices and stating changes if you modify the files.
  • Public domain or CC0 fonts usually carry no attribution requirement, but confirm the specific dedication.

For a website, a common practical step is keeping the license file in your project repository and, where the license asks for it, adding a credits note. Check the font's own terms rather than assuming a credits page is optional.

Verify character and language coverage

A font that looks right in a specimen may fail on your actual content. Before committing:

  1. List your required characters. Include punctuation, currency symbols, math signs, arrows, and any special glyphs your interface uses.
  2. Check the character set. Look for a glyph coverage list, a Unicode range table, or the font's documentation. Many open source fonts publish this on their project page.
  3. Test with real strings. Type sample content in the font, including names, product titles, and any non-Latin text. Watch for missing glyph boxes or automatic fallback to another font.
  4. Confirm language support. If you need accented Latin, Cyrillic, Greek, Arabic, or CJK coverage, verify it explicitly rather than inferring from the font's style.

A font can be perfectly licensed and still unusable for your project if it lacks a glyph you need.

Make sure the file format fits your software

Fonts are distributed in several formats, and not every tool accepts every one.

Format Typical use What to confirm
OTF / TTF Desktop apps, some web setups Your design or office software accepts the file
WOFF / WOFF2 Web pages Your build pipeline and target browsers support it
Variable font Responsive weight and width control Your software and browser support variable axes
Webfont kits Hosted or self-hosted web delivery The kit's license matches your intended use

Check the download contents before building around a font. If the listing offers only one format and your toolchain needs another, look for the upstream release, which often provides additional formats.

A quick pre-use checklist

  • [ ] License identified by name and version, with the text or a link saved
  • [ ] Attribution and notice requirements noted and assigned to someone
  • [ ] Reserved Font Name or modification restrictions understood
  • [ ] Required characters and languages tested with real content
  • [ ] File format confirmed against your design, web, or app toolchain
  • [ ] Upstream source checked if the listing lacks license details

Working through these points takes a few minutes per font and prevents the most common problem: discovering a licensing or coverage issue after a design is already in production.