Summary

The font-display descriptor determines how a font face is displayed based on whether and when it is downloaded and ready to use.

The Font Display Timeline

The font display timeline is based on a timer that begins the moment the user agent attempts to use a given downloaded font face. The timeline is divided into the three periods below which dictate the rendering behavior of any elements using the font face.

Font block period
If the font face is not loaded any element attempting to use it must render an invisible fallback font face. If the font face successfully loads during this period, it is used normally.
Font swap period
If the font face is not loaded any element attempting to use it must render a fallback font face. If the font face successfully loads during this period, it is used normally.
Font failure period
If the font face is not loaded the user agent treats it as a failed load causing normal font fallback.

Related at-rule@font-face
Initial valueauto
Mediavisual
Computed valueas specified
Canonical orderthe unique non-ambiguous order defined by the formal grammar

Syntax

/* Keyword values */
font-display: auto;
font-display: block;
font-display: swap;
font-display: fallback;
font-display: optional;

Values

auto
The font display strategy is defined by the user agent.
block
Gives the font face a short block period and an infinite swap period.
swap
Gives the font face no block period and an infinite swap period.
fallback
Gives the font face an extremely small block period and a short swap period.
optional
Gives the font face an extremely small block period and no swap period.

Formal syntax

[ auto | block | swap | fallback | optional ]

Examples

@font-face {
  font-family: ExampleFont;
  src: url(/path/to/fonts/examplefont.woff) format('woff'),
       url(/path/to/fonts/examplefont.eot) format('eot');
  font-weight: 400;
  font-style: normal;
  font-display: fallback;
}

Specifications

Specification Status Comment
CSS Fonts Module Level 4
The definition of 'font-display' in that specification.
Editor's Draft Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support60 No58 No47 Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic support6060 No58 No47 Yes

Document Tags and Contributors

 Last updated by: chrisdavidmills,