HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
When nesting an input
element inside a label
that has a for
attribute, the id
attribute of the input
is required to match it.
The label
element represents a caption in a user interface. The caption can be associated with a specific form control, known as the label element’s labeled control, either using the for
attribute, or by putting the form control inside the label
element itself.
When the input is inside the label
, there’s no need to specify a for
attribute as there can only be one input
, as in this example:
<label>
Age
<input type="text" name="age">
</label>
However, if the for
attribute is specified, then it must match the id
of the input
like this:
<label for="user_age">
Age
<input type="text" name="age" id="user_age">
</label>
Learn more:
Related W3C validator issues
When nesting a select element inside a label that has a for attribute, the id attribute of the select is required to match it.
The label element represents a caption in a user interface. The caption can be associated with a specific form control, known as the label element’s labeled control, either using the for attribute, or by putting the form control inside the label element itself.
When the select is inside the label, there’s no need to specify a for attribute as there can only be one select, as in this example:
<label>
Age
<select>
<option>young</option>
<option>old</option>
</select>
</label>
However, if the for attribute is specified, then it must match the id of the select like this:
<label for="age">
Age
<select id="age">
<option>young</option>
<option>old</option>
</select>
</label>
The <label> element represents a caption in a document, and it can be associated with a form input using the for attribute, which must be an ID. Document IDs cannot contain whitespace.
Example:
<form>
<label for="user_name">Name</label>
<input type="text" id="user_name" />
</form>
<label> tags are used to label inputs in form, which need to be present and visible in the document, for example:
<label for="age">Age</label>
<input id="age" />
The aria-* attributes are part of the WAI-ARIA (Web Accessibility Initiative-Accessible Rich Internet Applications) suite. They are used to improve the accessibility of web pages. However, when we use an input element with a type attribute whose value is hidden, we imply that the element is invisible and has no interaction with the user. Therefore, it doesn’t make sense to add aria-* attributes to it.
To fix this issue, you need to remove the aria-* attributes from the input element with type=hidden. Here is an example:
<!-- Wrong code -->
<input type="hidden" name="referer" value="https://example.com" aria-invalid="false">
<!-- Correct code -->
<input type="hidden" name="referer" value="https://example.com">
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 maxlength attribute can be used on an input element to define a client-side validation for the maximum length allowed on an input without resorting to JavaScript.
This attribute is only allowed on elements of type email, password, search, tel, text, or url.
The minlength attribute can be used on an input element to define a client-side validation for the maximum length allowed on an input without resorting to JavaScript.
This attribute is only allowed on elements of type email, password, search, tel, text, or url.
The minlength attribute defines the minimum number of characters (as UTF-16 code units) the user can enter into an <input> or <textarea>. This must be an integer value 0 or higher. If no minlength is specified, or an invalid value is specified, the input has no minimum length. This value must be less than or equal to the value of maxlength, otherwise the value will never be valid, as it is impossible to meet both criteria.
Here’s an example:
<label for="name">Enter your name (max 25 characters)</label>
<input type="text" minlength="25" id="name">
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 pattern attribute is only allowed on input whose type is email, password, search, tel, text or url. Check the type used, and consider changing to one of the allowed types to enable pattern client-side validation.
The pattern attribute is a handy way of adding client-side validation on HTML forms without resorting to JavaScript. Check out this article to learn more about Input Pattern.
The max attribute on an <input> element does not accept an empty string.
The max attribute defines the maximum value that is acceptable and valid for the input containing the attribute.
The name attribute is required for all input elements.
<input> elements can’t have a search role. Instead, try with <input type="search">.
<input> elements of type search are text fields designed for the user to enter search queries into. These are functionally identical to text inputs, but may be styled differently depending on the user agent.
The search role is a landmark. Landmarks can be used by assistive technology to quickly identify and navigate to large sections of the document. The search role is added to the container element that encompasses the items and objects that, as a whole, combine to create search functionality. When a <form> is a search form, use the search role on the form.
Example of a search form:
<form role="search">
<label for="search-input">Search this site</label>
<input type="search" id="search-input" name="search">
<input value="Submit" type="submit">
</form>
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.