Variable Font Analyzer
Inspect the fvar table of any variable font. See every registered axis (weight, width, slant, italic, optical size, grade, custom), with min, max, and default values. If the font is not variable, the tool reports that clearly.
Registered OpenType axes
- wght — Weight, from 1 to 1000 typically
- wdth — Width, from 50 to 200 typically
- ital — Italic, 0 (upright) or 1 (italic)
- slnt — Slant, in degrees (negative is right-slanted)
- opsz — Optical size, in points
- GRAD — Grade, for weight without affecting width
Custom axes are allowed but must use uppercase tags (for example, YTLC for y-transparency lower counter in Amstelvar).
Frequently asked questions
What is a variable font axis?
An axis is a design dimension that can be continuously adjusted — weight, width, slant, or optical size. Each axis is registered with a 4-character OpenType tag.
How do I use these axes in CSS?
Use font-variation-settings: "wght" 500, "wdth" 110; for direct control. For the common axes (weight, style, width, optical size), the individual CSS properties (font-weight, font-style, font-stretch, font-optical-sizing) are preferred because they are more performant and better supported.
Why does my font show no axes?
The font is not variable. Static fonts have fixed weight and width values. You would need to use multiple static font files instead of a single variable file.