CSS font-feature-settings Descriptor

The CSS font-feature-settings descriptor is used with the @font-face at-rule to define the inital settings for the font-feature-settings property when the @font-face at-rule is rendered.

The font-feature-settings descriptor is not to be confused with the font-feature-settings property. The font-feature-settings descriptor does not affect font selection. It is used solely with the @font-face at-rule to define the initial values for the font-feature-settings property, which can then be used elsewhere in the style sheet to change these values.

Official Syntax

The font-feature-settings descriptor has the following syntax (which is the same syntax that the font-feature-settings property uses):


The initial value is normal.

These values are explained below.

Specifies that that no change in glyph selection or positioning occurs due to this property.
This value specifies a case-sensitive OpenType feature tag (OpenType feature tags contain four ASCII characters). The value must be a valid string of four ASCII characters and be within the U+20-7E codepoint range.

This is an optional value that can be used for glyph selection. It must be a valid integer of 0 or more.

If the value is 0, the feature is disabled. If used on a boolean feature, a value of 1 enables the feature. When used on non-boolean features, a value of 1 or greater enables the feature and indicates the feature selection index.

If this value is omitted, a value of 1 is assumed.

Synonymous with 1.
Synonymous with 0.

Official Specifications

The font-feature-settings descriptor is defined in CSS Fonts Module Level 3 (W3C Candidate Recommendation 3 October 2013).