HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
The ::ng-deep CSS selector is often used in an Angular Component’s CSS to override the styles of a third-party component or a child component’s styles.
This CSS selector is now deprecated.
Learn more:
Related W3C validator issues
The ::file-selector-button has not been recognized by the W3C Validator. This seems to be a bug in the W3C Validator, which has already been reported.
The <table> element does not accept a height attribute. Use CSS instead.
A CSS definition for background-image could not be understood by the parser. Check its definition to ensure that it’s well formed and that it contains an appropriate value.
The value on the display property is not valid.
The display CSS property sets whether an element is treated as a block or inline element and the layout used for its children, such as flow layout, grid or flex.
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The specified CSS filter is not a standard one, and may only work in some browsers.
font-display isn’t a CSS property, it’s a descriptor for use with the @font-face at-rule.
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The value passed to the font-size property is invalid, probably missing the amount of px.
The font-size CSS property sets the size of the font, and this size can be expressed in different units, like em, % or px.
Example:
<!DOCTYPE html>
<html>
<head>
<title>Font-size Example</title>
<style>
p {
font-size: 16px;
}
</style>
</head>
<body>
<p>This is an example of a paragraph with a font-size of 16px.</p>
</body>
</html>This issue is a false positive by the W3C validator, fixed in the latest versions of Nu Validator.
The value revert is indeed a valid value for the CSS property font-size.
The @import CSS rule can be used to import a style sheet into another style sheet. It must appear at the top of the document, and after any @charset declaration.
The max-width CSS property sets the maximum width of an element. It prevents the used value of the width property from becoming larger than the value specified by max-width.
This property can express a value in different units like px, em, % or ch, and keyword values, but auto is not an allowed value.
Some examples of valid values for max-width:
/* <length> value */
max-width: 3.5em;
/* <percentage> value */
max-width: 75%;
/* Keyword values */
max-width: none;
max-width: max-content;
max-width: min-content;
max-width: fit-content(20em);
/* Global values */
max-width: inherit;
max-width: initial;
max-width: revert;
max-width: unset;25,000 HTML checks per month. Fully automated.
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