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Table of Contents
What and Actually Do
When to Use Them (and When Not To)
Tips for Getting It Right
Home Web Front-end HTML Tutorial How do I use the and elements to group and style table columns?

How do I use the and elements to group and style table columns?

Jun 29, 2025 am 02:11 AM
colgroup col

Use

<colgroup> and <col> to simplify table column style settings. 1. <colgroup> wraps multiple <col> tags, and can directly apply styles such as background color and width for the entire column; 2. It must be placed in the header of <table>, and supports the span attribute to define multiple column styles; 3. Only some CSS attributes are supported, and are not suitable for complex layouts or differentiated styles; 4. It is suitable for large tables or scenarios where cell structure cannot be controlled, but attention should be paid to browser compatibility and separation of structure and styles.

Styling table columns with <colgroup></colgroup> and <col> might not be the first thing you reach for when building a table, but it can save you time and make your CSS cleaner. These elements let you target entire columns directly in HTML without needing extra classes or JavaScript.

What <colgroup></colgroup> and <col> Actually Do

The <colgroup></colgroup> tag groups one or more <col> elements together, allowing you to apply styles to entire columns of a table. This is especially useful if you want to style every cell in a column the same way—like setting background color, width, or borders—with repeating styles on each <td> or <code><th> .<p> Here's a basic example:</p><pre class='brush:php;toolbar:false;'> &lt;table&gt; &lt;colgroup&gt; &lt;col span=&quot;1&quot; style=&quot;background-color: #f2f2f2; width: 150px;&quot;&gt; &lt;col span=&quot;1&quot; style=&quot;background-color: #e6e6e6;&quot;&gt; &lt;/colgroup&gt; &lt;tr&gt; &lt;th&gt;Header 1&lt;/th&gt; &lt;th&gt;Header 2&lt;/th&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt;Row 1 Data 1&lt;/td&gt; &lt;td&gt;Row 1 Data 2&lt;/td&gt; &lt;/tr&gt; &lt;/table&gt;</pre><p> In this case, the first column gets a light gray background and a fixed width, while the second has a slightly darker shade.</p><p> A few things to note:</p><ul><li> The <code><colgroup> must come right after the opening <table> tag.

  • You don't need to wrap every column in a <col> —you can use the span attribute to cover multiple columns at once.
  • Only a limited set of CSS properties will work (like width, background, border), so don't expect full styling support.
  • When to Use Them (and When Not To)

    These tags are most helpful when you're dealing with large tables where manually applying classes to each cell would be tedious. They're also handy when working with CMS-generated tables or content that doesn't allow much control over individual <td> elements.

    But there are some downsides:

    • Browser support is generally good, but quirks exist—especially with complex layouts.
    • If you need different styles within the same column (like alternative row colors), <colgroup> won't help.
    • It mixes presentation with HTML structure a bit, which isn't ideal from a separation-of-concerns standpoint.

    If you're using CSS frameworks or utility-first styles like Tailwind, you'll probably stick to class-based style instead.

    Tips for Getting It Right

    To avoid confusion and ensure consistent results:

    • Always place <colgroup> before any <thead> or <tr> elements inside your table.
    • Use the span attribute to reduce repetition. For example, if two adjacent columns should have the same width and background, just do:
       <col span="2" style="width: 100px; background: #ddd;">
    • Test across browsers. Some older versions may ignore certain styles applied via <colgroup></colgroup> .
    • Don't rely solely on <colgroup></colgroup> for layout. It's great for quick visual tweaks but not for precise positioning or responsive design.
    • Also keep in mind that only the first <colgroup></colgroup> in a table is respected by most browsers—so don't try to define multiple ones unless you know exactly how they'll behave.


      That's about it. Using <colgroup></colgroup> and <col> isn't complicated, but it's easy to overlook their limitations. If all you need is basic column styling, they can simplify your code quite a bit.

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