WordPress plugins often come in free and pro versions, with the pro version unlocking additional features. If you’ve developed a plugin and want to seamlessly integrate the pro version’s functionality into the free version, this step-by-step guide will help you achieve that through code and plugin development.

Step 1: Separate Your Versions

Begin by creating two separate plugins: one for the free version and another for the pro version. Each plugin should have its own directory and files. The free version will be available in the WordPress repository, while the pro version can be distributed separately, typically after users make a purchase.

Step 2: Modularize with Hooks and Filters

Utilize WordPress action and filter hooks to keep your code modular and extendable. In the free version, define hooks that can be utilized by the pro version to extend functionality. This ensures that both versions remain independent yet can interact seamlessly.

// In the Free Version Plugin
// Define a hook in the free version
do_action('free_version_hook');

// In the Pro Version Plugin
// Add functionality to the free version hook
add_action('free_version_hook', 'pro_version_functionality');
function pro_version_functionality() {
    // Your pro version code goes here

Step 3: Update Mechanism

Implement a mechanism in the pro version to detect the presence of the free version when users manually upload it. Use hooks in the free version to inject the pro version’s functionality into the existing codebase.

Step 4: User Instructions

Clearly document the process for users in the plugin documentation. Instruct users to install and activate the free version first, followed by uploading and activating the pro version. This ensures a smooth integration of features.

Step 5: Optional – Version Checking

Consider implementing version checking to ensure compatibility between the free and pro versions. This can help prevent issues that may arise if users are using outdated versions of either plugin.