The <frequency>
CSS data type represents a frequency dimension, such as the pitch of a speaking voice. It is not currently used in any CSS properties.
Syntax
The <frequency>
data type consists of a <number>
followed by one of the units listed below. As with all CSS dimensions, there is no space between the unit literal and the number.
Units
Hz
- Represents a frequency in hertz. Examples:
0Hz
,1500Hz
,10000Hz
. kHz
- Represents a frequency in kilohertz. Examples:
0kHz
,1.5kHz
,10kHz
.
Note: Although the number 0
is always the same regardless of unit, the unit may not be omitted. In other words, 0
is invalid and does not represent 0Hz
or 0kHz
. Though the units are case-insensitive, it is good practice to use a capital "H" for Hz
and kHz
, as specified in the SI.
Examples
Valid frequency values
12Hz Positive integer 4.3Hz Non-integer 14KhZ The unit is case-insensitive, though non-SI capitalization is not recommended. +0Hz Zero, with a leading + and a unit -0kHz Zero, with a leading - and a unit
Invalid frequency values
12.0 This is a <number>, not an <frequency>, because it is missing a unit. 7 Hz No space is allowed between the number and the unit. 0 Although unitless zero is an allowable <length>, it's an invalid <frequency>.
Specifications
Specification | Status | Comment |
---|---|---|
CSS Values and Units Module Level 3The definition of '<frequency>' in that specification. | Candidate Recommendation | Initial definition. |
Note: This data type was initially introduced in CSS Level 2 for the now-obsolete aural media type, where it was used to define the pitch of the voice. However, the <frequency>
data type has been reintroduced in CSS3, though no CSS property is using it at the moment.
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
<frequency>
|
Chrome
No support No |
Edge
No support No |
Firefox
No support No |
IE
No support No |
Opera
No support No |
Safari
No support No |
WebView Android
No support No |
Chrome Android
No support No |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
No support No |
Samsung Internet Android
No support No |
Hz unit
|
Chrome
No support No |
Edge
No support No |
Firefox
No support No |
IE
No support No |
Opera
No support No |
Safari
No support No |
WebView Android
No support No |
Chrome Android
No support No |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
No support No |
Samsung Internet Android
No support No |
kHz unit
|
Chrome
No support No |
Edge
No support No |
Firefox
No support No |
IE
No support No |
Opera
No support No |
Safari
No support No |
WebView Android
No support No |
Chrome Android
No support No |
Firefox Android
No support No |
Opera Android
No support No |
Safari iOS
No support No |
Samsung Internet Android
No support No |
Legend
- No support
- No support
<frequency> by Mozilla Contributors is licensed under CC-BY-SA 2.5.