This plugin hasn’t been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.

Only One Category


Only One Category makes sure users only select one category for their post by making the selectors radio buttons, which only allow one category to be selected.

Rather than spend all your time maintaining the editorial style of only putting posts into a single category, this plugin is a quick way for you to enforce that standard. It makes it impossible for a person to accidentally break your site’s layout of functionality by putting a post in multiple categories. They just can’t do it, whether by accident or intention.


  • How it’ll make the Categories section look while editing a post on the current version of WordPress.
  • How it looks when you Quick Edit a post with the new UI.


Activate the plugin. Now you should only see radio buttons where you previously saw category checkboxes. That’s why you downloaded it, right?


Why use this plugin?

The biggest reason that you might want to use this plugin is that your site is structured around the assumption that posts will exist in a single category. This makes it impossible for a person to accidentally break your site’s layout of functionality by putting a post in multiple categories.

If you have many contributors and don’t have the resources for a thorough editorial flow with checks and rechecks, the plugin is an easy quick way to make sure your standard is maintained without taking a lot of time correcting mistakes.

How does it work?

Plugin live-swaps check boxes for radio button before the pages are sent to users.

Are there any options?

Not currently. If they ever make sense — if for example we were to add the option to use it one all hierarchical taxonomies — it may possibly get one.


September 16, 2016
Hello, works perfectly for post, but I would like to have the same for my pages 🙂
September 3, 2016
Thank you David. Exactly what I wanted. Here is a suggestion: Allow an option to prevent selecting the top-level category, if there are sub-categories. Still display the top level, just don’t provide a button. Reason – because I only want the sub-categories to hold posts.
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Contributors & Developers

“Only One Category” is open source software. The following people have contributed to this plugin.


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Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.


1.0.4 (2016.02.25)

1.0.3 (2016.02.25)

  • David can’t count…

1.0.2 (2016.01.26)

  • Removed deprecated use of get_all_category_ids
  • Bumped tested version number

1.0.1 (2015.04.21)

  • VCS headaches…

1.0.0 (2015.04.21)

  • Some basic cleanup of code quality.
  • Making it not function for quick-edit, as it was broken and so far it’s not been worth fixing.

0.2.0 (2013.08.16)

  • Made plugin file’s description shorter.
  • Confirmed 3.6 compatibility.
  • Made catcher a properly hooked function.

0.1.5 (2013.07.23)

  • Shortened short description

0.1.4 (2013.07.23)

  • put screenshot in the wrong place. yay!

0.1.3 (2013.07.23)

  • git svn is hard * 2

0.1.2 (2013.07.23)

  • git svn is hard

0.1.1 (2013.07.23)

  • Documentation improvements

0.1.0 (2013.07.22)

  • Initial