HTML Checking for Large Sites

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" />

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>