Font Metrics Viewer
Inspect unitsPerEm, ascent, descent, xHeight, capHeight — and generate CSS font-metric-overrides.
Runs entirely in your browser — no upload, no registration.
What this tool does
Parses the head, hhea and OS/2 tables of any TTF/OTF and shows their raw metric values plus percentage overrides you can drop into @font-face.
Why you might need it
Matching web-font metrics to a system fallback prevents cumulative layout shift (CLS) at load time.
How to use it
- Drop a font file.
- Copy the % values into ascent-override, descent-override, line-gap-override.
Always review the included licence before commercial use. Do not remove copyright records, designer names, licensing metadata or embedding restrictions from any font you process.