How to check if css value is supported by the browser?

We can since a while test from javascript if a css rule if available in the context with CSS.supports.

(Since Firefox 22/ Chrome 28)

console.log(
CSS.supports("( transform-origin: 5% 5% )"),
"\n",
CSS.supports("( display: flex )"),
"\n ",
CSS.supports("( background-color: #12233212 )")
)

The CSS.supports() static methods returns a Boolean value indicating if the browser supports a given CSS feature, or not.

https://developer.mozilla.org/en-US/docs/Web/API/CSS/supports

To go further, we can possibly use this property for browser detection.

I assume you meant to check whether the vh value is supported, not whether specifically DIV#id bears it?

function cssPropertyValueSupported(prop, value) {
  var d = document.createElement('div');
  d.style[prop] = value;
  return d.style[prop] === value;
}
cssPropertyValueSupported('width', '1px');
// => true
cssPropertyValueSupported('width', '1vh');
// => maybe true, maybe false (true for me)
cssPropertyValueSupported('width', '1foobar');
// => false

There is the new API CSS.supports. Supported in most browsers except IE.

console.log(
  // CSS.supports(property, value)
  1, CSS.supports("text-decoration-style", "blink"),
  2, CSS.supports("display", "flex"),
  3, CSS.supports('--foo', 'red'),
  4, CSS.supports('(--foo: red)'),

  // CSS.supports(DOMstring)
  5, CSS.supports("( transform-origin: 5% 5% )"),
  6, CSS.supports("( transform-style: preserve ) or ( -moz-transform-style: preserve ) or " 
  + "( -o-transform-style: preserve ) or ( -webkit-transform-style: preserve )")
)

And there is a similar feature in CSS, the @supports feature query selector, also supported in most browsers except IE:

@supports (display: grid) {
  div {
    display: grid;
  }
}
@supports not (display: grid) {
  div {
    float: right;
  }
}