Have you ever run your website through Google PageSpeed Insights and spotted the “Preload key requests” warning? That message basically means your website is delaying critical assets like fonts, CSS, or JavaScript that the browser needs right away to render your page properly. When those assets load late, your Core Web Vitals suffer, especially metrics like Largest Contentful Paint (LCP). In this post, we’ll show you how you can properly preload key requests in WordPress so you can get faster Core Web Vitals and, ultimately, better performance and rankings.
By the end of this guide, you will understand what key requests are, why preloading those matters, how to find them, and exactly how to implement preloading in WordPress without breaking your website.
What are Key Requests in WordPress?
When Google talks about key requests, it is usually referring to files that are critical for your page to display correctly and quickly. These often include:
- Fonts, especially web fonts like Google Fonts that affect how text appears.
- CSS files, which control your website’s layout, spacing, and design.
- Sometimes JavaScript files, particularly ones that are needed early in the loading process.
These are considered “key” because if they load slowly or get pushed too far down the loading queue, your page will look incomplete or blank for too long. That delay directly hurts user experience and your Core Web Vitals.
Why Preloading Helps Core Web Vitals?
Preloading tells the browser, “Hey, this file is important, fetch it as soon as possible.” Instead of waiting for the browser to discover the file naturally while parsing the page, you give it a head start.
This is especially helpful for Largest Contentful Paint because fonts and CSS often block the visual rendering of above the fold content. When you preload key requests in WordPress, the browser can retrieve those assets earlier, reducing render delays and making your page visually complete much faster. In practice, this can mean lower LCP times and a smoother experience for visitors.
How to Identify Key Requests?
Before you start adding preload tags, you need to know which files actually need it. The easiest way is to use Google PageSpeed Insights.
- Run your website through PageSpeed Insights.
- Scroll down to the “Diagnostics” section.
- Look for a warning that says “Preload key requests.”
Under that warning, Google will list specific files that it believes should be preloaded. These are usually fonts like fonts.googleapis.com, CSS files like your theme’s style.css, or render blocking scripts. Make a note of these URLs because you will need them in the next step.
Adding Preload in WordPress via functions.php
One clean way to preload key requests in WordPress is by adding code to your theme’s functions.php file or a custom website plugin. This avoids installing extra plugins if you prefer to keep things lightweight.
Here is a simple example of how you might add a preload link for a CSS file:
function add_preload_links() {
echo '';
}
add_action('wp_head', 'add_preload_links');You would replace the URL with the actual file that PageSpeed Insights flagged. You can add multiple preload lines if needed, one for each key asset.
Example of intended use:
function add_preload_links() {
echo '<link rel="preload" href="/wp-content/themes/your-theme/fonts/myfont.woff2" as="font" type="font/woff2" crossorigin>';
echo '<link rel="preload" href="/wp-content/themes/your-theme/js/app.js" as="script">';
}
add_action('wp_head', 'add_preload_links');Be careful not to preload too many files. Preloading everything can backfire by competing for bandwidth and slowing things down instead of speeding them up.
Preloading Google Fonts (with caution)
Google Fonts are one of the most common triggers for the “Preload key requests” warning. Preloading them can help, but you need to do it thoughtfully.
If you are using Google Fonts via a link tag in your theme, you can preload the main font file like this:
function preload_google_fonts() {
echo '';
}
add_action('wp_head', 'preload_google_fonts');Example WordPress snippet:
function preload_google_fonts() {
echo '<link rel="preconnect" href="https://fonts.googleapis.com">';
echo '<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>';
echo '<link rel="preload" as="style" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;700&display=swap">';
echo '<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;700&display=swap" rel="stylesheet">';
}
add_action('wp_head', 'preload_google_fonts');Make sure you use the exact font file URL that your website is actually loading. Also include the crossorigin=”anonymous” attribute, which is required for font preloading to work properly in most browsers.
Alternatively, many performance plugins let you preload Google Fonts automatically, which can be easier if you are not comfortable editing code.
Caution: Preload only fonts your website actually uses above the fold. Over-preloading bloats bandwidth. Self-host via plugins like OMGF for full control and privacy wins.
Testing with PageSpeed Insights
After you preload key requests in WordPress, always test again in PageSpeed Insights. Run a new analysis and check whether the warning is gone or reduced.
Look at your Core Web Vitals scores, especially LCP. If they improved, you are on the right track. If not, you may need to adjust which files you are preloading or remove unnecessary ones.
It is also a good idea to test both mobile and desktop results, since performance can vary significantly between them.
Final Thoughts
Preloading key requests in WordPress can make a noticeable difference to how fast your pages render, how smooth your site feels, and how Google evaluates your Core Web Vitals. By identifying truly critical assets, telling the browser to fetch them early, and validating your changes with PageSpeed Insights, you can turn a technical warning into a real performance win.
If you care about speed, rankings, and user experience, take a few minutes today to check your website and start preloading key requests in WordPress.
