How To Add Custom Code In WordPress

You'll often find code to insert while researching some WordPress problem. Most people who come across this for the first time, have no idea where to place it. The usual response is your theme's "functions.php". But this is a bad idea.

Why not Use Functions.php for WordPress Code?

Using functions.php to insert code in WordPress is dangerous for the following reasons.

First, your theme can change. And when it changes, the functions.php file changes as well. This means that you'll have to port your entire code over to the new theme's functions.php. It's an additional step that's inconvenient, and that you might forget.

The second reason is much more serious. Errors in functions.php will crash your entire site. That's because the theme itself is corrupt. WordPress doesn't know how to deal with a problematic functions.php file without bringing down the theme itself. Simple syntax errors will break your site, and that is a very dangerous thing.

For this reason, I prefer to use a custom plugin for adding code instead. And this article will show you how to do it.

Step 1: Create the Directory and File on your Desktop

On your PC, create a folder with a name like "namehero-plugin-code". Inside that folder, create a new file with a ".php" extension with the same name (namehero-plugin-code.php). Here's an image of the folder and file:

Directory Structure

Step 2: Paste the Basic Plugin Code into the PHP File

Open the PHP file you created in Step 1, and paste the following code into it:

/* Plugin Name: NameHero Custom Code Plugin
Description: Place to insert custom code into WordPress

This is the skeleton custom plugin code. After installation, the "Plugin Name" will appear in your list of plugins.

Step 3: Compress the Folder with the File Inside it

WordPress allows us to upload only "zip" files. So right-click the folder, navigate to "Send to", and select "Compressed (zipped) Folder" as shown here:

Create a Zipped Folder with the Plugin

This will create a single zipped file that we're ready to upload in WordPress

Step 4: Installing the Plugin via the Zip File

Navigate to your WordPress dashboard, and click "Plugins->Add New" as shown here:

Add New Plugin

Now click the "Upload Plugin" button at the top. This will open up a section allowing you to choose a file from your desktop. Click the button, select the file, and select "Install Now":

Choose File and Install Now

This will install upload and install the plugin. When that's done, we just need to activate it as shown here:

Activate Plugin

Now the plugin will appear in the list of your installed plugins.

Step 5: Adding Code to the New Custom Plugin

It's time to add our code to the plugin!

Sanitize the Code

Let's say you come across a site that asks you to install some PHP code into WordPress. The first thing you need to do is check if it starts with:


Or if it ends with:


If the answer is "yes" to either, remove both of them. Basically ensure that the code on the website doesn't start with <?php , or end with ?> . This is very important.

Edit the Plugin and Insert the Code

Next, go to the WordPress dashboard and navigate to "Plugins->Editor" as shown here:

Plugin Editor

In the next screen, select the custom plugin we just added from the drop-down box on the top right-hand corner as shown here and hit "Select":

Select and Edit Custom Plugin

This will now allow us to add code to the plugin. Paste the sanitized code you got from the previous step into the text editor as shown here:

Place to Add Custom Code in WordPress

After that, click "Update File" and you're done! You've successfully inserted custom code into your WordPress in a safe and flexible way. This code will remain regardless of which theme you choose, and it won't crash your site if something goes wrong either!

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