Candidate Recommendation Draft · css-speech

CSS Speech

19 properties defined by this specification, 2 of them known to at least one browser (the others are badged Not in any browser yet).

Modern CSS features in this module: @counter-style.

Read the Editor's Draft ↗ W3C Candidate Recommendation Draft ↗

Each feature in detail

`cue`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<'cue-before'> <'cue-after'>?

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: see individual properties
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: see individual properties
Canonical order: per grammar
Animation type: see individual properties
Longhands: cue-before, cue-after

Specification ↗

`cue-after`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<url> <decibel>? | none

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`cue-before`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<url> <decibel>? | none

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`pause`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<'pause-before'> <'pause-after'>?

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: see individual properties
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: see individual properties
Canonical order: per grammar
Animation type: see individual properties
Longhands: pause-before, pause-after

Specification ↗

`pause-after`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<time [0s,∞]> | none | x-weak | weak | medium | strong | x-strong

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`pause-before`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<time [0s,∞]> | none | x-weak | weak | medium | strong | x-strong

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`rest`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<'rest-before'> <'rest-after'>?

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: see individual properties
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: see individual properties
Canonical order: per grammar
Animation type: see individual properties
Longhands: rest-before, rest-after

Specification ↗

`rest-after`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<time [0s,∞]> | none | x-weak | weak | medium | strong | x-strong

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`rest-before`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<time [0s,∞]> | none | x-weak | weak | medium | strong | x-strong

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`speak`

Property Limited availability

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

auto | never | always

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: auto
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: discrete

Browser support

First browser version supporting speak
Chrome	≤80
Edge	≤80
Firefox	No
Safari	No
Chrome Android	≤80
Safari iOS	No

First version with support, from MDN browser-compat-data.

Specification ↗

`speak-as`

Property Baseline: widely availablesince March 2026 Modern CSS: @counter-style

MDN The speak-as descriptor specifies how a counter symbol constructed with a given will be represented in the spoken form. For example, an author can specify a counter symbol to be either spoken as its numerical value or just represented with an audio cue.

Live preview Example from MDN

@counter-style speak-as-example {
  system: fixed;
  symbols:     ;
  suffix: " ";
  speak-as: numbers;
}

.list {
  list-style: speak-as-example;
}

<ul class="list">
  <li>I had one apple</li>
  <li>I ate two bananas</li>
  <li>I devoured three oranges</li>
  <li>I am not hungry for dinner</li>
  <li>But I'll have five scoops of ice cream for dessert</li>
</ul>

Syntax

normal | spell-out || digits || [ literal-punctuation | no-punctuation ]

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: normal
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: discrete

Browser support

First browser version supporting speak-as
Chrome	91
Edge	91
Firefox	33
Safari	No
Chrome Android	91
Safari iOS	No

First version with support, from MDN browser-compat-data.

Specification ↗ MDN reference ↗

`voice-balance`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<number> | left | center | right | leftwards | rightwards

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: center
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: the specified value resolved to a <number> between -100 and 100 (inclusive)
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`voice-duration`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

auto | <time [0s,∞]>

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: auto
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`voice-family`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

[ <voice-family-name> | <generic-voice> ]# | preserve

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: implementation-dependent
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: discrete

Specification ↗

`voice-pitch`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<frequency [0Hz,∞]> && absolute | [ [ x-low | low | medium | high | x-high ] || [ <frequency [0Hz,∞]> | <semitones> | <percentage> ] ]

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: medium
Applies to: all elements
Inherited: yes
Percentages: refer to inherited value
Computed value: one of the predefined pitch keywords if only the keyword is specified by itself, otherwise an absolute frequency calculated by converting the keyword value (if any) to a fixed frequency based on the current voice-family and by applying the specified relative offset (if any)
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`voice-range`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

<frequency [0Hz,∞]> && absolute | [ [ x-low | low | medium | high | x-high ] || [ <frequency [0Hz,∞]> | <semitones> | <percentage> ] ]

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: medium
Applies to: all elements
Inherited: yes
Percentages: refer to inherited value
Computed value: one of the predefined pitch keywords if only the keyword is specified by itself, otherwise an absolute frequency calculated by converting the keyword value (if any) to a fixed frequency based on the current voice-family and by applying the specified relative offset (if any)
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`voice-rate`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

[ normal | x-slow | slow | medium | fast | x-fast ] || <percentage [0,∞]>

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: normal
Applies to: all elements
Inherited: yes
Percentages: refer to default value
Computed value: a keyword value, and optionally also a percentage relative to the keyword (if not 100%)
Canonical order: per grammar
Animation type: by computed value type

Specification ↗

`voice-stress`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

normal | strong | moderate | none | reduced

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: normal
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: specified value
Canonical order: per grammar
Animation type: discrete

Specification ↗

`voice-volume`

Property Not in any browser yet

No prose in the spec's definition and no MDN page yet: the spec link below is the only description.

Syntax

silent | [ [ x-soft | soft | medium | loud | x-loud ] || <decibel> ]

Formal grammar from the specification, as webref extracts it: the latest level's definition, sometimes ahead of what browsers implement.

Definition

Initial: medium
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: silent, or a keyword value and optionally also a decibel offset (if not zero)
Canonical order: per grammar
Animation type: by computed value type

Specification ↗