One of the annoyances about the default tag cloud widget in WordPress is that there is no easy way to change the minimum and maximum font size that the widget uses. While the recent release of WordPress 2.8 doesn’t add any UI to change those sizes, it’s now easier to change them than before.

WordPress 2.8 adds a new widget_tag_cloud_args filter, which you can use to override the default arguments that are passed to the wp_tag_cloud function. The filter provides a keyed array, where the smallest, largest, and unit keys represent the smallest font size, the largest font size, and the unit (‘pt’, ‘em’, ‘px’, etc) used by the default tag cloud widget.

You can change the minimum and maximum font size that the default tag cloud widget uses in WordPress 2.8 by creating a new plugin that hooks that filter as explained below.

Create a new text file called orz-tag-cloud.php. Copy and paste the following code into that text file, changing the relevant values (shown in bold) as desired, and save it.

Create a new directory called orz-tag-cloud in your wp-content/plugins directory, and upload orz-tag-cloud.php to the new directory. Finally, activate the plugin by logging into WordPress as an administrator, selecting Plugins from the menu, and selecting Activate for the Orzeszek Tag Cloud plugin.

Make sure that the very first characters in orz-tag-cloud.php are <? and that the very last characters are ?>. If they’re not (for instance, if you have a space after ?>), you may get a ‘Warning: Cannot modify header information – headers already sent…’ message. More info.

Update 1: I updated the plugin to be even simpler and more streamlined. I had originally adapted the plugin from a more complex plugin that provides certain functionality specific to my blog. The original class structure was unnecessary for this simple plugin, however.

Update 2: I updated the instructions to place the orz-tag-cloud.php in its own folder to minimise the potential for conflicts with other plugins.

Update 3: Added a note indicating the cause of the ‘Warning: Cannot modify header information – headers already sent…’ message, and how to avoid it.