Are you interested in creating your own WordPress plugin?
This step-by-step tutorial will teach you the basics of creating a WordPress plugin from scratch. You’ll learn how plugins are structured and how to add custom functionality using WordPress hooks. If you can read basic PHP, you can follow along — no advanced programming required.
Prefer to watch? Here’s the video walkthrough:
What is a WordPress plugin?
A WordPress plugin is a package of code that adds features to your site. Every plugin lives in its own folder inside wp-content/plugins/. At minimum, a plugin is a single PHP file with a special header comment that tells WordPress “I’m a plugin.”
Plugins can do anything from tiny tweaks (like adding a message after each post) to full applications (like turning WordPress into an online store).
What you’ll need
- A WordPress site to experiment on — a local install or staging site is ideal, so mistakes don’t affect visitors.
- A plain text editor (Notepad, VS Code, or similar).
- A way to access your site’s files: FTP, your host’s file manager, or the built-in Plugin File Editor.
Back up first. Before touching any code, make sure you have a recent backup. A free plugin like UpdraftPlus takes minutes to set up and can save you hours.
Step 1: Create the plugin folder and file
In wp-content/plugins/, create a new folder called my-first-plugin. Inside it, create a file called my-first-plugin.php.
Giving the folder and the main file the same name is a WordPress convention — it keeps things tidy and avoids conflicts.
Step 2: Add the plugin header
Open my-first-plugin.php and paste this at the top:
<?php
/**
* Plugin Name: My First Plugin
* Description: Adds a thank-you message after post content.
* Version: 1.0
* Author: GetStartedWP
*/
That comment block is the plugin header. It’s how WordPress recognizes the file as a plugin. If you go to Plugins > Installed Plugins now, you’ll see “My First Plugin” listed — but activating it does nothing yet, because we haven’t added any functionality.
Step 3: Add functionality with a filter
WordPress has a system called hooks that lets plugins tap into what WordPress is doing. A filter hook lets you modify a piece of data — like post content — before it’s displayed.
Add this below the header:
if ( ! defined( 'ABSPATH' ) ) exit;
function gswp_thank_you_message( $content ) {
if ( is_single() ) {
$content .= '<p><em>Thanks for reading! If this tutorial helped, share it with a friend.</em></p>';
}
return $content;
}
add_filter( 'the_content', 'gswp_thank_you_message' );
Here’s what each part does:
if ( ! defined( 'ABSPATH' ) ) exit;— a security line that stops the file from running if accessed directly.- The function takes the post content, appends a message to it, and returns the result. The
is_single()check means it only runs on individual post pages, not archives. add_filter( 'the_content', ... )— attaches our function to WordPress’sthe_contentfilter, which processes every post’s content before display.
Step 4: Activate and test
Go to Plugins > Installed Plugins, find “My First Plugin,” and click Activate. Open any blog post on your site — you should see your thank-you message below the content.
If something breaks, don’t panic: rename the plugin folder via FTP and WordPress will deactivate it automatically.
Where to go next
- Want to modify post content without building a full plugin? See how to insert content at the bottom of every post with a filter.
- Want to customize how your site looks instead? Learn how to create a WordPress child theme.
- From here, the natural next steps are learning about action hooks (which let you do things at specific moments, like sending an email when a post publishes) and the Settings API for adding an options page.
You just built a working WordPress plugin from scratch. Everything else in plugin development is a variation on what you did here: hook into WordPress at the right moment, and run your code.
