Free Browser Compatibility Testing on Mozilla Firefox 48 Browser Online

ELEMENTS NOT SUPPORTED IN MOZILLA Firefox 48 BROWSER

CSS3 attr() function for all properties

While attr() is supported for effectively all browsers for the content property, CSS Values and Units Level 3 adds the ability to use attr() onany CSS property, and to use it for non-string values (e.g. numbers, colors).

CSS @apply rule

Allows a set of CSS properties to be applied using a named variable

CSS image-set

Method of letting the browser pick the most appropriate CSS background image from a given set, primarily for high PPI screens.

:placeholder-shown CSS pseudo-class

Input elements can sometimes show placeholder text as a hint to the user on what to type in. See, for example, the placeholder attribute in HTML5. The :placeholder-shown pseudo-class matches an input element that is showing such placeholder text.

selector list argument of :not()

Selectors Level 4 allows the :not() pseudo-class to accept a list of selectors, which the element must not match any of. Selectors Level 3 only allowed :not() to accept a single simple selector. Thus, :not(a):not(.b):not([c]) can instead be written as :not(a, .b, [c])

Media Queries: interaction media features

Allows a media query to be set based on the presence and accuracy of the user's pointing device, and whether they have the ability to hover over elements on the page. This includes the pointer, any-pointer, hover, and any-hover media features.

CSS hanging-punctuation

Allows some punctuation characters from start (or the end) of text elements to be placed "outside" of the box in order to preserve the reading flow.

:has() CSS relational pseudo-class

Only select elements containing specified content. For example, a:has(>img) selects all elements that contain an child.

CSS Device Adaptation

A standard way to override the size of viewport in web page using the @viewport rule, standardizing and replacing Apple's own popular viewport implementation.

CSS text-orientation

The CSS text-orientation property specifies the orientation of text within a line. Current values only have an effect in vertical typographic modes (defined with the writing-mode property)