Caching API Calls in WordPress Using Transients

Caching is an important technique to improve website performance. One way to improve the performance of a WordPress website is by caching API calls. In this post, we will show you how to cache API calls in WordPress using the Transients API.

The Transients API is a simple way to store temporary data in the WordPress database. It allows you to store data that will expire after a set amount of time. You can use the Transients API to cache API calls and improve the performance of your WordPress website.

To cache an API call using the Transients API, you can use the following function:

function cache_api_call( $url ) {
    $cache_key = 'api_call_' . md5( $url );
    $cache_time = 3600; // Cache for 1 hour

    // Try to get the cached data
    $cached_data = get_transient( $cache_key );

    // If the cached data exists, return it
    if ( $cached_data ) {
        return $cached_data;

    // If the cached data doesn't exist, make the API call
    $response = wp_remote_get( $url );

    if ( is_wp_error( $response ) ) {
        return false;

    $body = wp_remote_retrieve_body( $response );
    $data = json_decode( $body );

    // Save the data to the cache
    set_transient( $cache_key, $data, $cache_time );

    return $data;

This function takes a URL as its argument and generates a unique cache key based on the URL. It then tries to get the cached data for the cache key using the get_transient() function. If the cached data exists, it returns it. If the cached data doesn’t exist, it makes the API call using the wp_remote_get() function. If the API call is successful, it saves the data to the cache using the set_transient() function.

You can use this function to cache any API call in WordPress by passing the API URL as the argument. Just make sure to change the cache time to the appropriate value for your use case.

One thing to keep in mind is that caching API calls can sometimes result in stale data being served to users. If the API data changes frequently, you may need to adjust the cache time accordingly or implement a system to invalidate the cache when the data changes.

Caching API calls is a simple and effective way to improve the performance of a WordPress website. The Transients API makes it easy to cache data in WordPress, and the cache_api_call() function we’ve provided can be used to cache any API call. By using caching, you can reduce the load on your server and provide a better experience for your users.