A WordPress child theme is a WordPress theme that inherits its functionality from another WordPress theme, the parent theme. Child themes are often used when you want to customize or tweak an existing WordPress theme without losing the ability to upgrade that theme.
It works like this: you have a WordPress theme, but you want to make it your own by customizing it. You could modify the theme to meet your needs, but doing so creates a big problem in that WordPress themes are frequently updated. If you customize your theme, then update it, there’s a good chance that all of your changes will be lost.
You might think that you’ll just avoid updating your theme. Avoiding updates is a risky proposition. WordPress themes get updated for many reasons: to conform with new WordPress coding standards, to fix bugs, and to fix security issues.
Avoiding updates could break your site or even open you up to hacking. In other words, theme updates aren’t optional. If you want to maintain a secure and healthy WordPress site, you need to install theme updates as they become available.
By making changes to a child theme, you ensure that you can safely update your theme while maintaining site security and protecting your hard work.
Designers and developers use child themes to speed up their development. When using a good parent theme, you can drastically reduce the time it takes for you to create a WordPress site. All good parent themes aka theme frameworks offer tons of functionality and customization options, so you don’t have to code everything. DIY users often create child themes to tweak an existing theme without losing the ability to update the parent theme if needed.
Here’s the thing that causes the most confusion: You don’t always need a child theme.
So, how do you know whether or not you need a child theme? The answer depends on how you customize your theme.
Have you, or do you plan to, modify your theme’s underlying code? That includes any of the following:
- Edit the theme’s CSS stylesheet.
- Edit any of the theme’s PHP templates.
- Edit the theme’s functions.php file. Even just to add a single line of code.
If you answered yes to any of these questions, you need a child theme.
On the other hand, if your theme customizations are made exclusively through the WordPress dashboard, you don’t need a child theme. That includes changes made through the Theme Customizer (confusing, I know). The Theme Customizer doesn’t change your theme files.
Changes made through the Theme Customizer, or a theme settings page, are stored in a database. That means that theme updates won’t overwrite your changes.
Child themes add to the overall security of your website. They also make theme customization much easier. It’s possible to create a custom WordPress theme simply by modifying the CSS of your child theme. That makes theme customization accessible to designers who otherwise don’t code. Just remember to create your child theme first, then make changes to the child theme’s CSS file.
Child themes are also a great learning tool. When you’re just starting out working with WordPress themes, a child theme allows you to try all kinds of things without having to worry about breaking your theme. If things go wrong, you can get back to your original design simply by activating the parent theme.