WordPress Shortcodes: The Complete Guide

A shortcode lets you insert dynamic content into pages and posts.

A developer can create a shortcode once and website users can then insert it anywhere on the site.

Shortcodes let you add many useful features to your WordPress site without you, as a user, having to deal with PHP. By creating custom shortcodes, you can simplify content management and add custom functionality to your site.

And what can go inside a shortcode? Pretty much anything — from outputting a single word to loading a booking form.

Last updated: 4 March 2026

Note: More advanced users can create their own shortcodes. You can read this article as an overview of what's possible — or dive deeper and create your first shortcode. At the end of the article I show how to create your own plugin where you register the shortcode.

1. Creating a simple PHP function

First, let's see how to create a simple PHP function that adds two numbers together.

function my_simple_addition($a, $b) {
    $sum = $a + $b;
    echo "The sum of $a and $b is: $sum";
    return $sum;
}

This function takes two parameters ($a and $b), adds them together, outputs the result, and also returns the sum value.

If you wanted to use this function in a PHP template / custom plugin / PHP snippet, you would call it like this:

<?php my_simple_addition(5, 3); ?>

The result shown on the site where the code is inserted would be: "The sum of 5 and 3 is: 8".

A regular user won't be calling PHP functions directly, though. Let's solve that.

2. Creating a basic shortcode without arguments

We'll turn the function into a shortcode that can be used directly in page or post content — no PHP knowledge needed. We'll start with a simple shortcode that has no arguments.

// Simple function to demonstrate a shortcode without arguments
function simple_addition_shortcode() {
    // For simplicity, we'll add two fixed values
    $a = 5;
    $b = 3;
    $sum = $a + $b;

    return "The sum of $a and $b is: $sum";
}

// Register the shortcode
add_shortcode('add_basic', 'simple_addition_shortcode');

You can use your custom shortcode anywhere on the site using the WP Shortcode block:

[add_basic]

WordPress will replace it with the text: "The sum of 5 and 3 is: 8"

Note: Notice that the shortcode uses return instead of echo. This is because shortcodes must return the content that should be inserted into the page.

3. Adding arguments to a shortcode

Now let's improve our shortcode so it can accept input arguments, just like the original function did.

// Function to add two numbers
function my_simple_addition($a, $b) {
    $sum = $a + $b;
    return "The sum of $a and $b is: $sum";
}

// Shortcode function with arguments
function addition_shortcode($atts) {
    // Define default values for the attributes
    $atts = shortcode_atts(array(
        'a' => 0,
        'b' => 0,
    ), $atts, 'add');

    // Convert values to numbers for correct addition
    $a = floatval($atts['a']);
    $b = floatval($atts['b']);

    // Return the result of the function
    return my_simple_addition($a, $b);
}

// Register the shortcode
add_shortcode('add', 'addition_shortcode');

You can now use the shortcode with custom values in your pages or posts. I've also renamed the shortcode to "add":

[add a="10" b="20"]

This shortcode will output: "The sum of 10 and 20 is: 30"

4. A closer look at shortcode_atts()

The shortcode_atts() function is key to working with shortcode arguments. It takes three parameters:

1. Default values — an associative array of default values for the input arguments
2. Shortcode arguments — the values entered by the user
3. Shortcode name — used for filtering (optional)

$atts = shortcode_atts(array(
    'a' => 0,  // Default value for argument 'a' is 0
    'b' => 0,  // Default value for argument 'b' is 0
), $atts, 'add');

This function sets default values for any arguments the user didn't provide.

5. Practical tips and recommendations

Where to put the code

You can place your shortcode:

1. In a custom plugin — the recommended approach.
2. In functions.php of a child theme — less ideal.
3. In a PHP snippet via a plugin like Code Snippets — the least recommended option.

Creating a custom plugin for shortcodes

<?php
/**
 * Plugin Name: My Custom Shortcodes
 * Description: A plugin containing useful shortcodes for the site
 * Version: 1.0
 * Author: Your Name
 */

// Shortcode for addition
function my_simple_addition($a, $b) {
    $sum = $a + $b;
    return "The sum of $a and $b is: $sum";
}

function addition_shortcode($atts) {
    $atts = shortcode_atts(array(
        'a' => 0,
        'b' => 0,
    ), $atts, 'add');

    $a = floatval($atts['a']);
    $b = floatval($atts['b']);

    return my_simple_addition($a, $b);
}
add_shortcode('add', 'addition_shortcode');

// You can add more shortcodes here

Watch out for name conflicts

Shortcode names must be unique, otherwise they can conflict with other plugins. Consider adding a prefix specific to your site or plugin:

add_shortcode('mysite_add', 'addition_shortcode');

Using a shortcode in PHP code

If you need to use a shortcode inside PHP code (for example in a template), use the do_shortcode() function:

<?php echo do_shortcode('[add a="10" b="20"]'); ?>

Need a shortcode?

Need a shortcode but don't feel like writing it? Get in touch and we'll figure something out. 😉