You might see <colgroup> Element reference while reading someone else’s HTML, or need it while building a page of your own. Instead of memorizing a definition, look at a working example and see when the element makes sense.
The Idea in Plain English
Groups columns in a table before the row sections. It is for column metadata, not row content.
For a reference page, pay attention to where the element is allowed, whether it needs a closing tag, and what other elements it can contain.
A Working Example
Read the sample once before copying it. Notice the element names and attribute values, then compare them with the explanation below.
<table>
<colgroup>
<col span="1">
<col span="2">
</colgroup>
<tr><th>Name</th><th>Math</th><th>Science</th></tr>
<tr><td>Leo</td><td>88</td><td>92</td></tr>
</table>What Each Part Does
- The colgroup groups column definitions.
- A table represents information arranged in related rows and columns.
- The col element describes a table column without containing its cells.
The first column and next two columns are described as separate column groupings.
Try It Yourself
Try replacing the example content with your own while keeping the valid HTML structure.
Common Beginner Mistakes
- Mixing a colgroup span attribute with child col elements.
- Changing several parts of the example at once, making it difficult to see which part caused a different result.
- Choosing a tag only because its default appearance looks right, without checking whether it describes the content correctly.
Key Takeaways
- Groups columns in a table before the row sections. It is for column metadata, not row content.
- The first column and next two columns are described as separate column groupings.
- Test the markup in a browser, and check accessibility and real-world behavior where relevant.