HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
HTML issues tagged as bad value.
The value contact is not a valid option for the autocomplete attribute on an <input> element.
All HTML elements may have the hidden boolean attribute set. When specified on an element, it indicates that the element is not yet, or is no longer, relevant, so browsers won’t render it.
Boolean attributes don’t accept values, its presence represents the true value and its absence represents the false value.
<!-- This is invalid because the hidden attribute should not have a value set -->
<div hidden="false"></div>
<!-- The correct way to hide a div is like this -->
<div hidden>This will be hidden</div>
<!-- And to show the element, we just don't hide it -->
<div>This won't be hidden</div>An <a> element has been found with an invalid href attribute, containing more than one # adjacent character.
The # is used to separate the fragment part of an URI (typically used to indicate a section within a document). For example, this is a valid link to a URI containing a fragment:
<a href="https://example.com/faqs#pricing">pricing</a>The next example is invalid because it contains two adjacent # characters, so that the fragment part would be #pricing instead of pricing:
<a href="https://example.com/faqs##pricing">pricing</a>The href attribute of an <a> element contains an invalid character, that should be properly encoded as a URI percent-encoded character.
6,250 HTML checks per week. Fully automated.
Save time using our automated web checker. Let our crawler check your web pages on the W3C Validator.
The src attribute on an <img> element contains an invalid character, that should be properly encoded as a URI percent-encoded character.
<a> tags can be used to link to an email address using the mailto protocol in the href attribute. Ensure that there is no space in the email address.
<a href="mailto: liza@example.com">This is wrong as it contains an space</a>
<a href="mailto:liza@example.com">This is OK</a>Still checking your large sites one page at a time?
Save time using our automated web checker. Let our crawler check your web pages on the W3C Validator.
The at symbol (@) should be percent-encoded as %40 in order to include it at an href attribute.
A <pattern> element has been found with an invalid ID. Check the format of the ID and ensure it does not start with a digit, full stop (.) or hyphen (-).
The <pattern> element is used within <svg> elements, which use XML 1.0 syntax. That syntax specifies that valid IDs only include designated characters (letters, digits, and a few punctuation marks), and do not start with a digit, a full stop (.) character, or a hyphen-minus (-) character.
The media attribute on a <link> element has not been recognized.
This attribute specified what media the linked resource is optimized for. As an example, the following will link a general stylesheet, and a specific one for printing:
<head>
<link rel="stylesheet" type="text/css" href="general.css">
<link rel="stylesheet" type="text/css" href="print.css" media="print">
</head>Valid values for this attribute include:
- all. Default, used for all media.
- print. Used for printers and print previews.
- screen. Used for computer, tablets or smartphone screens.
The src attribute value is malformed, check that it doesn’t contain extraneous characters.
For example, this is invalid because the URL in the src attribute contains a space in between the https: and // parts:
<a href="https: //example.com">Some link</a>To fix this issue, you can try removing the space after “https:” in the URL in the src attribute:
<a href="https://example.com">Some link</a>25,000 HTML checks per month. Fully automated.
Save time using our automated web checker. Let our crawler check your web pages on the W3C Validator.