`::-webkit-meter-suboptimum-value` CSS pseudo-element

Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The ::-webkit-meter-suboptimum-value pseudo-element styles the <meter> element when the value attribute falls outside of the low-high range and is not equivalent to the optimum value.

Yellow is the default color.

Syntax

::-webkit-meter-suboptimum-value {
  /* ... */
}

Examples

This example will only work in browsers based on WebKit or Blink.

HTML

Normal:
<meter min="0" max="10" low="3" high="7" optimum="6" value="2">
  Score 2/10
</meter>
<br />
Styled:
<meter id="styled" min="0" max="10" low="3" high="7" optimum="6" value="2">
  Score 2/10
</meter>

CSS

body {
  font-family: monospace;
}

.safari meter {
  /* Reset the default appearance for Safari only */
  /* .safari class is added via JavaScript */
  -webkit-appearance: none;
}

#styled::-webkit-meter-suboptimum-value {
  background: linear-gradient(
    to bottom,
    #ffff77,
    #999900 45%,
    #999900 55%,
    #ffff77
  );
  height: 100%;
  box-sizing: border-box;
}

JavaScript

// Safari requires <meter> elements to have an `appearance` of `none` for custom styling
// using `::-webkit-meter-*` selectors, but `appearance: none` breaks rendering on Chrome.
// Therefore, we must check if the browser is Safari-based.

const isSafari =
  navigator.userAgent.includes("AppleWebKit/") &&
  !navigator.userAgent.includes("Chrome/");

if (isSafari) {
  document.body.classList.add("safari");
}

Result

Specifications

Not part of any standard.

Browser compatibility

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`-webkit-meter-suboptimum-value`	12	79	No	15	5.1	18	No	14	5	1.0	4.4	5