font-variation-settings CSS property provides low-level control over variable font characteristics, by specifying the four letter axis names of the characteristics you want to vary, along with their values.
font-variation-settingswill always override those set using the corresponding basic font properties, e.g.
font-weight, no matter where they appear in the cascade.
/* Use the default settings */ font-variation-settings: normal; /* Set values for variable font axis names */ font-variation-settings: "XHGT" 0.7; /* Global values */ font-variation-settings: inherit; font-variation-settings: initial; font-variation-settings: unset;
This property's value can take one of two forms:
<string>of 4 ASCII characters followed by a
<number>indicating the axis value to set. If the
<string>has more or fewer characters or contains characters outside the U+20 - U+7E codepoint range, the whole property is invalid. The
<number>can be fractional or negative, depending on the value range available in your font, as defined by the font designer.
Variable font axes come in two types: registered and custom.
Registered axes are the most commonly encountered — common enough that the authors of the specification felt they were worth standardizing. Note that this doesn't mean that the author has to include all of these in their font.
Here are the registered axes along with their corresponding CSS properties:
|Axis Tag||CSS Property|
Custom axes can be anything the font designer wants to vary in their font, for example ascender or descender heights, the size of serifs, or anything else they can imagine. Any axis can be used as long as it is given a unique 4-character axis. Some will end up becoming more common, and may even become registered over time.
Note: Registered axis tags are identified using lower-case tags, whereas custom axes should be given upper-case tags. Note that font designers aren't forced follow this practice in any way, and some won't. The important takeaway here is that axis tags are case-sensitive.
Warning: In order to use variable fonts on your operating system, you need to make sure that it is up to date. For example Linux OSes need the latest Linux Freetype version, and macOS prior to 10.13 does not support variable fonts. If your operating system is not up to date, you will not be able to use variable fonts in web pages or the Firefox Developer Tools.
The following live example's CSS can be edited to allow you to play with font weight values.
The following live example's CSS can be edited to allow you to play with font slant/oblique values.
|CSS Fonts Module Level 4 |
The definition of 'font-variation-settings' in that specification.
|Working Draft||Initial definition|
|Applies to||all elements. It also applies to
|Computed value||as specified|
|Animation type||a transform|
|Canonical order||per grammar|
|Basic support||62||17|| 62
|Android webview||Chrome for Android||Edge Mobile||Firefox for Android||Opera for Android||iOS Safari||Samsung Internet|
|Basic support||62||62||17|| 62
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.