HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
HTML issues tagged as th.
A <table> contains an incoherent number of cells on one of its columns. Check the structure of the table to find the invalid column.
Example of a valid table that defines in its header that the first column is 2 cells wide:
<table>
<thead>
<tr>
<th colspan="2">The table header</th>
</tr>
</thead>
<tbody>
<tr>
<td>The table body</td>
<td>with two columns</td>
</tr>
</tbody>
</table>
This same table with an empty body will be invalid because the table header cannot match any body columns:
<table>
<thead>
<tr>
<th colspan="2">The table header</th>
</tr>
</thead>
<tbody>
</tbody>
</table>
The <th> HTML element defines a cell as a header of a group of table cells, and must appear within a <tr> element.
In the following example for a simple table, the first <tr> contains two <th> header cells naming the values for each column:
<table>
<tr>
<th>Name</th>
<th>Age</th>
</tr>
<tr>
<td>Liza</td>
<td>49</td>
<tr>
<tr>
<td>Joe</td>
<td>47</td>
</tr>
</table>
50,000 Accessibility and HTML checks per month. Fully automated.
Let our automated scanner check your large sites using Axe Core and W3C Validator.