WordPress 6.8 in plain English: the 7 changes worth your time

If you have ever clicked a link and felt the next page appear before your brain finished the thought, that is the feeling we are after. WordPress 6.8 brought that experience closer to default reality with Speculative Loading. Marketers care because it lifts perceived speed and conversion. Developers care because it is finally a standard, low effort way to get instant page transitions on a classic multi page site. And it is built into Core, which means no brittle hacks or mystery scripts.

I will keep it human. First we will translate the idea, then we will switch seats between marketer and dev, and you can steal whichever parts you need.

What Speculative Loading actually is

Browsers have a fairly sharp new trick called the Speculation Rules API. You give the browser a short set of rules that say which internal links are likely to be clicked next, and how confident you are. The browser can then prefetch a target page or go further and prerender it in the background. When the visitor clicks, the page appears almost immediately. Prefetch is lighter. Prerender is heavier but feels like magic.

WordPress 6.8 wires this API up for you. Out of the box, Core uses a conservative prefetch profile for logged out visitors, and only when you use pretty permalinks. The defaults avoid admin screens, login, query string URLs, and any links marked nofollow. This keeps it safe for the broadest set of sites.

If you remember the old resource hints, this is not the same thing. Those were about subresources like CSS or fonts. Speculative Loading targets whole page navigations, which is perfect for multi page sites, shops, and blogs.

Why marketers should care

Speed changes the way people move through a site. When the next article or product page shows up instantly, bounce tends to drop and deeper sessions are more common. You also get a nudge on the Core Web Vitals side, because faster navigations help the new responsiveness metric, Interaction to Next Paint, which replaced FID in March last year. If your reporting still talks about FID, it is due for a tidy up.

One thing to remember. Lab tests can miss this improvement, because speculative work happens only when a real person actually hovers or gestures toward a link. You will see the benefit in field data over time, not in a single Lighthouse run. That is normal.

So the marketer playbook looks like this.

1. Enable or keep the default conservative mode.

2. Watch your Core Web Vitals field data and user journeys over a few weeks. Use Search Console and PageSpeed Insights to keep an eye on INP and LCP in the field.

3. If your team is comfortable, consider moving some high intent paths to a more confident setting such as prerender on hover. Test this on a small slice first.

I will show you how to do those changes safely in a minute.

How WordPress sets it up for you

Core prints a small block of speculation rules on the page and applies a sensible rule set. By default, the mode is prefetch with conservative eagerness. That means the browser waits for strong hints, such as a hover or pointer down, before fetching the next page. WordPress also exposes two controls that matter in the real world. A configuration filter to pick mode and eagerness, and a filter to exclude specific paths from speculative work.

There is also a simple escape hatch in the editor. Add the class no prefetch or no prerender on any block, and links inside that block will opt out. This is handy for footers full of utility links, heavy downloads, or anything that should never be touched until clicked.

If you prefer a UI, the Speculation Rules plugin gives you a settings screen where you can choose prerender with moderate eagerness for a more aggressive result. Think of it as training wheels while you learn.

Quick wins for typical sites

A few patterns make immediate sense.

Editorial sites
Leave Core on conservative prefetch for most journeys. Then, for in article suggested reads and the next article module, test moderate prerender. People hover and click those a lot, which means a high chance of payoff with little waste.

Product catalogues
Category to product and product to related product are classic high intent flows. Prefetch is usually enough, but moderate prerender on hover can be lovely on mobile where tap intent is clearer.

Support portals and knowledge bases
Users skim back and forth quickly. Prefetch gives them that glide between pages without burning too much memory.

Places to avoid
Never prerender cart, checkout, account, or any page with side effects. Core already excludes a lot, but these are worth double checking on your own stack.

Developer notes you will actually use

You can change the Core configuration with a tiny filter. If you want to trial pre-render with moderate eagerness, drop this into a safe snippet location.

// Force a specific mode and eagerness.
add_filter( 'wp_speculation_rules_configuration', function( $config ) {
return array(
'mode' => 'prerender', // 'prefetch' or 'prerender'
'eagerness' => 'moderate', // 'conservative', 'moderate', 'eager'
);
} );

When you need to exclude sensitive routes, use the path filter. The function gives you the current mode as a second parameter which is sometimes useful for conditional logic.

// Exclude cart, checkout, and account from speculative loading.
add_filter( 'wp_speculation_rules_href_exclude_paths', function( $paths, $mode ) {
$paths[] = '/cart/*';
$paths[] = '/checkout/*';
$paths[] = '/my-account/*';
return $paths;
}, 10, 2 );

If you need to disable the feature for a short period during a test, this is the one line switch.

add_filter( 'wp_speculation_rules_configuration', '__return_null' );

window.performance.getEntriesByType('navigation').at(0).activationStart;

add_filter( 'wp_speculation_rules_href_exclude_paths', function( $paths ) {
foreach ( array( '/cart/*', '/checkout/*', '/account/*' ) as $p ) {
$paths[] = $p;
}
return $paths;
}, 10, 2 );

add_filter( 'wp_speculation_rules_configuration', function( $config ) {
return array( 'mode' => 'prerender', 'eagerness' => 'moderate' );
} );

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