CSS voice-stress

The CSS voice-stress property is used in speech media to adjust the strength of stress emphasis.

The voice-stress property works by applying a combination of pitch change, timing changes, loudness changes, and other adjustments which can be used to increase or decrease the strength of stress emphasis.

Stress emphasis can have different meanings in different languages, so the actual meaning of the values used will depend on the language being used.


Possible Values

Specifies that the default emphasis should be used.
Prevents any emphasis on text that would normally be emphasized.
Specifies that moderate emphasis should be used. This is more emphasis than would normally be produced (i.e. it's more emphasis than when using the normal keyword).
Specifies that strong emphasis should be used. This is more emphasis than moderate would produce.
Specifies that any emphasis should be reduced (i.e. not as much emphasis as would normally be applied).

In addition, all CSS properties also accept the following CSS-wide keyword values as the sole component of their property value:

Represents the value specified as the property's initial value.
Represents the computed value of the property on the element's parent.
This value acts as either inherit or initial, depending on whether the property is inherited or not. In other words, it sets all properties to their parent value if they are inheritable or to their initial value if not inheritable.

General Information

Initial Value
Applies To
All elements.

Example Code

Official Specifications

Vendor Prefixes

For maximum browser compatibility many web developers add browser-specific properties by using extensions such as -webkit- for Safari, Google Chrome, and Opera (newer versions), -ms- for Internet Explorer, -moz- for Firefox, -o- for older versions of Opera etc. As with any CSS property, if a browser doesn't support a proprietary extension, it will simply ignore it.

This practice is not recommended by the W3C, however in many cases, the only way you can test a property is to include the CSS extension that is compatible with your browser.

The major browser manufacturers generally strive to adhere to the W3C specifications, and when they support a non-prefixed property, they typically remove the prefixed version. Also, W3C advises vendors to remove their prefixes for properties that reach Candidate Recommendation status.

Many developers use Autoprefixer, which is a postprocessor for CSS. Autoprefixer automatically adds vendor prefixes to your CSS so that you don't need to. It also removes old, unnecessary prefixes from your CSS.

You can also use Autoprefixer with preprocessors such as Less and Sass.