HTML Checking for Large Sites
Rocket Validator automatically scans your sites for accessibility issues using the W3C Validator,
hosted on our own servers and integrated into our web crawler.
When was the last time you validated your whole site?
Keep your sites healthy checking for A11Y/HTML issues on an automated schedule.
The “width” attribute on the table (or td) element is obsolete. Use CSS instead.
Both <table> and <td> elements no longer accept a width attribute. Instead, you should use CSS as in this example:
<table style="width:100%;">
<tr>
<td style="width:50px;">Name</td>
</tr>
</table>Related W3C validator issues
The <table> element does not accept a height attribute. Use CSS instead.
The <iframe> element, used to embed another document inside the current document, accepts both attributes width and height which must be valid non-negative integers. Percentages are not allowed for these attributes.
Check the iframe spec.
<img> elements accept a width attribute to specify the size in pixels. This value can only be an integer, it should not contain units or %. If you need to specify a percentage width, you can do that with CSS:
<img src="photo.jpg" alt="red car" style="width:100%;">
The width attribute on <img> elements expects a digit to indicate the number of pixels. Ensure that this attribute contains only digits.
For example:
<!-- This is invalid because width is not a digit -->
<img width="225px" alt="cat" src="cat.jpg" />
<!-- This is valid -->
<img width="225" alt="cat" src="cat.jpg" />
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 specified CSS filter is not a standard one, and may only work in some browsers.
Check out the Filter Effects W3C Working Draft
Padding properties, unline margin properties, don’t accept negative values. Read more about the CSS box model
CSS styles could not be parsed, check the indicated line to find what caused the parser to fail. Common causes are unclosed curly brackets or comments, missing semicolons or unexpected or empty properties.
Read more about CSS: Cascading Style Sheets syntax
A CSS definition for an X property could not be understood by the parser. Check it to ensure that it’s well formed and that it contains an appropriate value.
<td> elements no longer accept an align attribute. This can be achieved using CSS like this:
<td style="text-align:center;">content</td>
<img> tags no longer accept a border attribute. This can be defined using CSS instead, for example:
<img src="..." alt="..." style="border:0;" />
The <center> tag is no longer valid in HTML, you should use CSS instead, for example:
<p style="text-align:center">this text will be centered</p>
The <caption> element specifies the caption (or title) of a table. It’s not allowed for a <caption> to contain another table.
The <font> element, used to define the font face, size and color in previous versions of HTML, is no longer valid in HTML5. Instead, you should rely on CSS styles.
For example, you can define a font size of 12px, bold text with inline styles like this:
<p style="font-size: 12px; font-weight: bold;">some text</p>
Learn more about CSS fonts:
<td> elements no longer accept a valign attribute. This can be achieved using CSS like this:
<td style="vertical-align:middle;">content</td>
You’re using an attribute X that is no longer valid for element Y, but you can use CSS to achieve the same effect.
When was the last time you validated your whole site?
Keep your sites healthy checking for A11Y/HTML issues on an automated schedule.