WooCommerce Hooks and Filters: Complete Guide with Examples

This article was last manually reviewed for data accuracy on 08 November 2025.

WooCommerce hooks and filters are the developer’s ways to safely modify or extend WooCommerce store functionality without ever editing core files.

This comprehensive pillar guide is essential for any WooCommerce developer or serious store owner, explaining the critical differences between WooCommerce action hooks (add_action()) and WooCommerce filter hooks (add_filter()). 

Master these concepts to ensure your customizations are secure, performant, and completely update-proof across all future versions of the platform.

What Are WooCommerce Hooks?

WooCommerce hooks are the code injection points embedded within the platform’s core functions and templates, allowing developers to safely extend and modify functionality without altering source files. 

These hooks act as precise markers, signaling where custom PHP code can be safely attached using the core WordPress functions, add_action() or add_filter().

The hook system ensures update-proof customization. Rather than risk breaking your store by directly editing templates, you simply “plug” new logic into an existing hook point. 

WooCommerce inherits this robust architecture directly from WordPress, utilizing the do_action() and apply_filters() calls to power the entire ecosystem. 

Deep Dive: WordPress Hooks vs WooCommerce Hooks : Key Differences Explained

Mastering this system is fundamental to professional, scalable WooCommerce development.

WooCommerce Action Hooks vs Filter Hooks: Key Differences

While all WooCommerce hooks provide safe customization points, they are categorized into two fundamentally different types of WooCommerce hooks: WooCommerce Actions and WooCommerce Filters. 

Understanding their distinct purpose is the single most important concept in WooCommerce development.

What Are WooCommerce Action Hooks? (add_action Guide)

WooCommerce action hooks allow you to run custom functions at specific, predetermined events throughout WooCommerce’s execution flow.

When WooCommerce reaches a do_action() call, it halts momentarily to execute any custom functions attached by add_action(), then continues its process. Actions primarily handle side effects and tasks.

Common Use Case of WooCommerce Action Hooks

Running a task, such as sending an email, logging activity, or injecting custom HTML/scripts.

php
// Action hook example: Runs a function after the order has been processed.
add_action( 'woocommerce_thankyou', 'ar_custom_thankyou_message' ); 
function ar_custom_thankyou_message() {
    // This function performs a task (outputs HTML). 
    echo '<p>Thanks for your order! Your payment is being verified.</p>';
}

What Are WooCommerce Filter Hooks? (add_filter Guide)

WooCommerce filter hooks allow you to intercept and modify data before it is saved, processed, or displayed to the user. Before WooCommerce outputs data (like a price, button text, or field value), it passes that value through an apply_filters() call. 

Your callback function, attached using add_filter(), receives the data, modifies it, and must return the altered value back to WooCommerce for display.

Common Use Case of WooCommerce Filter Hooks

Modifying existing text, dynamically changing prices, or altering product data arrays.

php
// Filter hook example: Intercepts the default button text and modifies it.
add_filter( 'woocommerce_product_single_add_to_cart_text', 'ar_custom_cart_button' );
function ar_custom_cart_button( $text ) {
    // This function receives the $text, modifies it, and returns the new value.
    return 'Add This Awesome Product!'; 
}

The key to using WooCommerce filter hooks correctly is the mandatory return statement. Without it, the value passed back to WooCommerce will be null, potentially leading to errors.

Why Use WooCommerce Hooks? Benefits for Update-Safe Customization

It is recommended to use WooCommerce Hooks instead of editing the templates directly because:

• Update-Safe: Hooks make your changes persist through WooCommerce core updates, preventing your custom logic from being overwritten.
• Granular Control: You can target extremely specific processes with minimal side effects, ensuring code is lean and robust.
• Scalability: Hooks promote modular code that is portable across sites and keeps custom logic separate from the theme layer.
• Community Standard: This is the native, official, and professional way to extend WooCommerce functionality, used by core developers and major plugin authors worldwide.

WooCommerce action hooks execute tasks using add_action(), while WooCommerce filter hooks modify data using add_filter() and a mandatory return statement. Internalizing this distinction is the foundation for writing clean, reliable, and update-proof custom code.

WooCommerce Hook Syntax: Mastering add_action() and add_filter()

WooCommerce hook syntax consists four arguments. You must understand the purpose of each of these arguments to utilize the WooCommerce hook framework properly.

The WooCommerce Hook Signature

Both types of WooCommerce hooks use the same function signature:

add_action( 'hook_name', 'your_function_name', $priority, $accepted_args );
add_filter( 'hook_name', 'your_function_name', $priority, $accepted_args );

Priority: Controlling Execution Order

The $priority parameter is a numeric value that dictates the execution order relative to other functions hooked to the same action.

• Lower numbers = Earlier execution. (e.g., Priority 5 runs before Priority 10).
• The default priority is 10.
• Using a higher number (e.g., 20 or 99) ensures your code runs after most theme or plugin code, which is useful for overriding or cleaning up output.

Deep Dive: WooCommerce Hook Priority: Execution Order & Best Practices

PHP

// Example: Two functions hooked to wp_head
add_action( 'wp_head', 'ar_early_message', 5 );  // Runs FIRST (Lowest number)
add_action( 'wp_head', 'ar_late_message', 15 ); // Runs LATER

Accepted Arguments: Receiving Context

The $accepted_args parameter tells WooCommerce how many parameters your callback function expects. If the hook provides data (e.g., the $order_id), you must match this count.

PHP

// WooCommerce passes the $order_id to this hook. We must accept 1 argument.
add_action( 'woocommerce_order_status_completed', 'ar_send_shipping_notification', 10, 1 ); 

function ar_send_shipping_notification( $order_id ) {
    // Logic uses the $order_id passed by WooCommerce.
    $order = wc_get_order( $order_id ); 
    // ...
}

The Mandatory Return Value in WooCommerce Filter Hooks

The add_filter() function is used to change something or modify data. While it shares the same parameters, the critical difference is: the return value.

The Mandatory Return

A filter hook intercepts data, modifies it, and must return the final value. If a filter function does not explicitly return a value, it can cause silent errors or break output in WooCommerce.

PHP

// Example: Changing the 'Add to Cart' button text

add_filter( 'woocommerce_product_single_add_to_cart_text', 'ar_change_button_text' ); 

function ar_change_button_text( $text ) {
    // $text is the original value passed in.
    return 'Buy This Now'; // CRITICAL: The modified value MUST be returned.
}

Receiving Multiple Arguments

Many powerful WooCommerce filter hooks pass multiple arguments—the original value plus context (e.g., the product object, cart item array, or current price). You must define the correct accepted_args count to receive them.

PHP

// The filter passes the $price (1st arg) and the $product object (2nd arg).

add_filter( 'woocommerce_get_price_html', 'ar_price_suffix', 10, 2 ); 

function ar_price_suffix( $price, $product ) { // Must define 2 parameters
    // We can now use both pieces of data to modify the $price.
    return $price . ' (tax included)'; 
}

Common Patterns in Hook Usage

The examples above illustrate the two most fundamental patterns for using WooCommerce hooks:

Practical WooCommerce Hook Examples: Product, Cart, and Admin Customization

This section provides real-world WooCommerce hook examples for key areas of the storefront and dashboard, serving as a rapid reference for WooCommerce customization.

• Product Page Hooks – Add and Modify Product Information
• Cart and Checkout Hooks – Customize Customer Flow
• Order and Email Hooks – Extend WooCommerce Communication
• Admin Hooks – Add Features to the WooCommerce Dashboard

The breadth of WooCommerce hook examples demonstrates that nearly every aspect of the platform—from frontend design to backend operation—is extensible. Rely on action hooks for running tasks (e.g., saving data, displaying HTML) and filter hooks for modifying existing values (e.g., changing text, adjusting query arguments).

For a deep dive to target specific product, user, cart and more: read WooCommerce Conditional Hooks: A Developer’s Guide to Targeted Logic for Pages, Products & Categories

How to Find WooCommerce Hooks in Theme and Plugin Files

Finding the correct hook is often the biggest challenge in WooCommerce customization. While no single list of WooCommerce hooks can cover every custom plugin, three professional methods allow you to instantly identify the exact action or filter needed for your custom code.

Deep Dive: Find WooCommerce Hooks & Filters: A Complete Developer Guide

Searching do_action and apply_filters in Code

The most reliable, low-level method for how to find WooCommerce hooks is direct code inspection. Every hook point in the entire WordPress and WooCommerce ecosystem is defined by one of two core functions:

• Action Hook: Defined by do_action( ‘hook_name’ )
• Filter Hook: Defined by apply_filters( ‘hook_name’, $value, … )}, which passes and returns data.

Workflow:

1. Open the WooCommerce plugin folder or the active theme files in your code editor (VS Code, PhpStorm).
2. Search the entire codebase for do_action and apply_filters.
3. Reading the surrounding lines of code will instantly reveal the context in which the hook fires and identify any variables passed to your function (the accepted arguments).

Using Developer Tools and Plugins (Simply Show Hooks)

For a real-time, visual approach to hook identification, several tools log and display triggers as the page renders:

• WP Hooks Finder: A lightweight plugin that overlays the names of available action and filter hooks directly onto the WooCommerce frontend (Product, Cart, Checkout pages). This provides an instant, visual map of injection points.
• Query Monitor: A comprehensive developer tool that includes a dedicated “Hooks & Actions” tab. This logs every hook that fires during a request, along with its execution order, making it invaluable for debugging priority conflicts.

Pro Tip: Bookmark our WooCommerce Hooks Visual Guides as a ready reference.

Exploring WooCommerce Core for Available Hooks

While the methods above find hooks in any plugin, the safest source for the list of WooCommerce hooks is the official documentation:

• Official WooCommerce Developer Hook Reference: Consult the official documentation maintained by WooCommerce. This resource documents the parameters, file locations, and triggering conditions for core actions and filters.
• GitHub Repository: New hooks are often added between major updates. Checking the WooCommerce GitHub repository is a professional habit for viewing the latest code and newly available action or filter points.

The best workflow combines these methods: use a visual tool like Query Monitor to quickly identify the hook location, then confirm the exact arguments it accepts by searching for the do_action() or apply_filters() call in the WooCommerce source code.

How to Create Custom WooCommerce Hooks (do_action and apply_filters)

Professional WooCommerce developers regularly introduce custom hook points to ensure their themes or plugins are extensible and maintainable. By defining your own custom WooCommerce hooks, you allow other developers to inject code or modify values without altering your primary files.

Creating Custom Action Hooks (do_action)

A custom action hook should be created when you want others to run additional functions or logic at a specific point in your code’s execution. The do_action() function merely signals that an event has occurred and calls all registered callbacks (add_action) in order of priority.

Implementation Syntax:

PHP

// Code runs BEFORE the hook is called...
// ...
do_action( 'my_plugin_after_data_save', $post_id, $data_array );
// ...
// Code runs AFTER all custom actions have executed.

Creating Custom Filter Hooks (apply_filters)

A custom filter hook should be created when you need to provide a mechanism for other code to intercept and modify a value before it is used by your code.

The apply_filters() function takes the original value, passes it through all registered filters, and returns the modified result.

Implementation Syntax:

PHP

// Define the default value

$default_value = 'Initial Value';

// Pass the default value through the filter

$final_value = apply_filters( 'my_plugin_setting_value', $default_value, $context_variable );

// The code continues using the $final_value

echo $final_value;

When to Create Your Own Hooks

Creating custom WooCommerce hooks is a best practice for any code designed for reusability, distribution, or complex client projects. Use them when you identify a point where future functionality might need to:

1. Inject Content/Logic (Action): Add analytics scripts, display conditional messages, or trigger external API calls based on your code’s events.
2. Alter Data (Filter): Dynamically change output text, adjust calculation results, or modify configuration arrays used by your functions.

How to Remove WooCommerce Hooks (remove_action and remove_filter)

To maintain complete control, you often need to remove an existing WooCommerce hook added by a theme or plugin.

The key to successful removal is to match the original add_action() or add_filter() registration exactly. This means you must match the hook name, callback function name, and the optional priority argument.

Deep Dive: How to Safely Remove & Override WooCommerce Hooks

Example: Removing the Shop Sorting Dropdown

To remove the default sorting menu on the shop page, you must target the specific parameters used by WooCommerce core:

PHP

// WooCommerce registers this with priority 30.

// add_action( 'woocommerce_before_shop_loop', 'woocommerce_catalog_ordering', 30 );

// To remove it, match the function name and priority precisely:

remove_action( 'woocommerce_before_shop_loop', 'woocommerce_catalog_ordering', 30 );

WooCommerce Hooks Best Practices for Secure and Update-Proof Code

Implementing WooCommerce hooks and filters requires adhering to professional WooCommerce best practices to ensure your custom code is update-proof, modular, and conflict-free. Always isolate your customizations using the methods below to guarantee safe WooCommerce customization.

Use Child Themes or Custom Plugins for Code Placement

Never insert custom code directly into core WooCommerce files or the parent theme’s files, as it will be lost during updates. Utilize one of these safe environments based on your project size and requirements:

• Custom Site-Specific Plugin (Recommended for Professionals)
  • Best for: Modular, reusable, and site-wide customizations.
  • Advantage: This method is the gold standard for safe WooCommerce customization. It keeps custom logic completely separate from the theme, ensuring it remains active and version-controlled even if you switch themes.
• Child Theme’s functions.php File
  • Best for: Small, theme-specific tweaks (e.g., design adjustments or display functions).
  • Limitation: Code disappears if the theme is changed, and performance can suffer if this file becomes too large or complex.
• Code Snippets Plugin (Beginner-Friendly)
  • Best for: Testing simple hooks without editing files.
  • Advantage: Offers a secure administrative UI to toggle snippets on/off individually, reducing the risk of fatal errors.

Keep Functions Modular and Conflict-Free

To avoid name collision and ensure scalability, adopt a strict naming convention for all your custom functions and hook names:

• Use a Unique Prefix: Always prefix your function names (e.g., ar_custom_thankyou_message) and any custom hooks you define (e.g., do_action(‘ar_plugin_after_save’)). This practice prevents conflicts with functions used by WooCommerce core or third-party plugins.
• Encapsulate Logic (Modular): Keep individual callback functions focused on a single responsibility. Instead of writing one massive function, use multiple, smaller, modular functions that hook into different action or filter points.

Test Hook Timing and Priority Levels

Unpredictable behavior often happens from timing issues. Understanding and testing the priority and accepted_args is essential for reliable code execution:

• Master Priority: Control the execution order using the priority parameter. Use a number less than 10 to ensure your code runs before default WooCommerce functions, or a number greater than 10 (e.g., 99) to ensure your code runs last (useful for overriding output).
• Confirm Arguments: Always verify the number of arguments (parameters) the hook accepts. If a hook passes two arguments, you must define 2 in your add_action() or add_filter() call, even if you only use one of them:
• Use Developer Tools: Leverage tools like Query Monitor to visually inspect the order in which hooks are firing, confirming that your custom code is executing at the intended time and location.

For a deep dive on fixing WooCommerce hook conflicts, read: The Ultimate Guide to Fix and Debug WooCommerce Hook Conflicts

Common WooCommerce Hook and Filter Mistakes (and How to Fix Them)

Even experienced developers encounter issues where “WooCommerce hooks not working” is the result of simple, yet critical, syntax or timing errors. Understanding these common WooCommerce errors and their fixes saves significant debugging time.

Hook Name or Priority Issues

The most frequent reason a hook fails is a precise mismatch between the hook registration and the custom function.

Missing Return Values in Filters

This is a classic “common WooCommerce error” for beginners. A filter hook must handle data and pass it back into the system.

The Mistake: Forgetting the return statement in a filter callback function.

PHP

// Fails: This function does not return a value, causing silent errors or blank output.

add_filter( 'woocommerce_order_button_text', 'ar_broken_text' );

function ar_broken_text( $text ) {

    $text = 'Confirm & Pay';

    // MISSING return $text; 

}

The Fix: Every single $\text{add\_filter()}$ callback function must return the modified value (even if the value wasn’t changed).

PHP

// Correct: The $text value is received, modified, and returned.

function ar_fixed_text( $text ) {

    return 'Confirm & Pay Now'; // Correctly returns the value

}

Hook Execution Timing Problems

Hooks often fail because the custom code runs too early or too late in the WordPress loading process.

WooCommerce Hooks FAQ: Frequently Asked Questions

This WooCommerce hooks FAQ section addresses the most common WooCommerce action filter questions and technical queries from developers and store owners.

What is the main difference between an action hook and a filter hook?

An Action Hook add_action is used to do something at a specific point, like outputting HTML or sending an email. It does not return a value. A Filter Hook add_filter is used to change something by modifying data (e.g., product price, button text) that is passed to it. Filters must return the modified data.

Where is the best place to add WooCommerce hook code?

The best practice is to create a site-specific custom plugin to store all your custom code snippets. This ensures your customizations are portable, update-proof, and independent of your theme. For smaller, theme-specific tweaks, a child theme’s functions.php file is also acceptable.

How do I find a specific hook on a WooCommerce page?

Use a developer plugin like WP Hook Finder or Query Monitor to visually display all action and filter hook names running on the page. Alternatively, search the WooCommerce plugin files for the core functions: do_action and apply_filters.

Can I use hooks to change the WooCommerce checkout page?

Yes, extensively. You can add, remove, or modify checkout fields, custom messages, and button labels entirely through hooks. For example, the woocommerce_checkout_fields filter allows full control over form inputs, and woocommerce_after_order_notes allows adding content.

What does “priority” mean in a WooCommerce hook?

Priority is a numerical argument (defaulting to 10) that determines the order of execution when multiple functions are attached to the same hook location. A lower number (e.g., 5) runs earlier, and a higher number (e.g., 20) runs later.

How do I remove a default WooCommerce action or filter?

Use remove_action() or remove_filter(). You must match the hook name, the function name, and the priority number exactly as they were originally registered. The removal code should be placed inside a later loading action, such as init or wp, to ensure the original hook has already been defined.

Summary – Key Takeaways for WooCommerce Hooks and Filters

Mastering WooCommerce hooks and filters transforms you from a customizer into a professional, scalable developer. This system is the foundation of clean, modular, and future-proof development, granting you precise control over every aspect of your store’s behavior without ever editing a core file.

Every customization scenario—from complex API integration to simple text changes—relies on finding the correct hook and utilizing its parameters safely.

Key Takeaways for Developers:

• Purpose: Use action hooks add_action to perform tasks (e.g., display content, send an email) and filter hooks add_filter to modify data (e.g., change prices, text). Filters must always return a value.
• Placement: Keep all custom logic in a site-specific plugin for maximum scalability, portability, and guaranteed update-safety.
• Discovery: Use developer tools like Query Monitor or direct codebase searches for do_action(} and apply_filters(} to locate the right trigger points.
• Precision: Control execution order using the priority argument (lower numbers run first; default is 10) and ensure you match the accepted_args count exactly.
• Removal: When removing hooks via remove_action() or remove_filter(), you must mirror the function name, hook name, and priority used in the original registration.
• Extensibility: Document and prefix any custom WooCommerce hooks you create to make your own code future-proof and ready for collaboration.

References and Further Reading

To continue your mastery of WooCommerce hooks and filters and deepen your understanding of the underlying architecture, the following official developer resources are indispensable:

• WooCommerce Developer Docs (Official Hook Reference):
  • The primary source for locating and confirming the exact names, arguments, and file locations for all core WooCommerce actions and filters.
• WordPress Plugin Handbook (Extensibility Documentation):
  • Essential reading for understanding the foundational WordPress hook system do_action and apply_filters upon which all WooCommerce customization is built.
• GitHub WooCommerce Repository:
  • The direct source for reviewing the latest core code. This is invaluable for inspecting the context and variables passed by a hook when the documentation is not explicit or to find recently added triggers.