Creating a Simple Custom Plugin in WordPress

admin

PHP, WordPress

September 25, 2025

Skills

WordPress is incredibly flexible, largely thanks to its plugins. In this article, we’ll explore what plugins are, how to manage them, and even write a simple one yourself.

What is a WordPress Plugin?

A WordPress plugin is a piece of software that adds new functionality to your WordPress site. It can range from simple features like displaying a custom message to complex systems like e-commerce or SEO management.

• Plugins help you extend WordPress without editing core files.
• Thousands of free and premium plugins are available in the WordPress repository.
• Common examples: contact forms, SEO tools, sliders, and security enhancements.

Think of a plugin as a “modular add-on” that can be installed or removed without breaking your website.

Enabling and Disabling Plugins

Managing plugins in WordPress is straightforward:

1. Log in to your WordPress dashboard.
2. Go to Plugins → Installed Plugins.
3. Click Activate to enable a plugin or Deactivate to disable it.

💡 Tip: Always deactivate a plugin before deleting it. Some plugins store settings in the database, and deactivating first prevents potential issues.

Plugins vs functions.php

A common beginner question is:

“Should I put custom code in functions.php or write a plugin?”

• functions.php:
  • Part of your theme.
  • Code here runs only while that theme is active.
  • Good for small tweaks tied to the theme.
  • Part of your theme.
  • Code here runs only while that theme is active.
  • Good for small tweaks tied to the theme.
  • Part of your theme.
  • Code here runs only while that theme is active.
  • Good for small tweaks tied to the theme.
  • Part of your theme.
  • Code here runs only while that theme is active.
  • Good for small tweaks tied to the theme.
• Plugins:
  • Independent of the theme.
  • Can be activated/deactivated at will.
  • Ideal for site-wide functionality that shouldn’t be lost if you change themes.

✅ Rule of thumb: If your code is useful even after switching themes, use a plugin.

Writing a Simple Plugin

Let’s create a simple plugin that displays a “Hello, WordPress!” message at the top of every post.

1. Create a Plugin Folder
   In wp-content/plugins/, create a new folder called hello-plugin.
2. Create a Main PHP File
   Inside hello-plugin, create hello-plugin.php and add the following:

<?php
/*
Plugin Name: Hello Plugin
Description: Displays a friendly message.
Version: 1.0
Author: Your Name
*/

// Function to display the greeting
function hello_world() {
    echo "Hello, WordPress!";
};

hello_world();

3. Note: Minimum requirement is to put the plugin name line in PHP comments.
4. Activate the Plugin
   • Go to WordPress dashboard → Plugins → Installed Plugins.
   • Find Hello Plugin and click Activate.

Now, every single post on your site will start with a friendly “Hello, WordPress!” message.

Conclusion

Plugins are one of the most powerful features of WordPress. They allow you to:

• Add new functionality without touching core files.
• Keep code modular and portable across themes.
• Enhance your site safely and efficiently.

By writing even a simple plugin, you gain a foundation to explore more advanced WordPress development. Once you’re comfortable, you can build plugins that do almost anything!