Font Metrics Fixer

About Vertical Metrics

Vertical metrics determine the baseline in a text and the space between lines of text. For historical reasons, there are three pairs of ascender/descender values, known as hhea, OS/2 and usWin metrics. Depending on the font, operating system and application a different set will be used to render text on the screen.

• Mac

  On the Mac, Safari and Chrome use the hhea values to render text. Firefox will respect the useTypoMetrics setting and will use the OS/2 if it is set. If the useTypoMetrics is not set, Firefox will also use metrics from the hhea table.

• Windows

  On Windows, all browsers use the usWin metrics, but respect the useTypoMetrics setting and if set will use the OS/2 values.