Core guide · Font technology
Variable fonts explained simply
Understand variation axes, file size, browser use and when a variable font is useful.
A variable font stores a range of styles—such as weight, width or slant—inside one coordinated file and lets compatible software select positions between its defined extremes.
Axes and instances
Common registered axes include weight, width, optical size, italic and slant. A font can also define named instances such as Regular or Bold so it behaves like a familiar family while still allowing continuous adjustment.
Performance is contextual
One variable file can replace several static files, but it is not automatically smaller than every possible subset. For a website that uses only one weight, a carefully subset static font may be lighter. Test the actual files and the styles the page needs.
- Load only used character sets.
- Preload only critical files.
- Use WOFF2 for modern web delivery.
- Provide sensible fallback fonts.
Check application support
Modern browsers and many design applications support variable fonts, but controls differ. Font Trust identifies variation axes from the file and provides an interactive specimen only on the font page, protecting catalogue speed.
This guide explains general font practice and the permissions displayed by Font Trust. The complete licence attached to a specific font remains the controlling text.