The Best Perfmatters Settings for WooCommerce

WooCommerce is powerful, but it is heavy. Out of the box it loads cart and checkout scripts on every single page of your site, even the ones with no shop content on them. If you want a fast store, the best Perfmatters settings for WooCommerce are mostly about telling those scripts to stay where they belong.

I run Glide Marketing, a UK web and SEO agency, and I set Perfmatters up on client WooCommerce stores regularly. This guide is the process I actually follow. It is practical, it is cautious, and it will keep your checkout working if you follow it in order. If you do not already have the plugin, you can get Perfmatters here.

One warning before we start. A WooCommerce store takes real money through the checkout. Never make speed changes on a live store without a backup, and never skip the testing step. Breaking checkout to save half a second is a terrible trade.

Start with a baseline

Before you change anything, take a proper before picture. Run PageSpeed Insights on three pages: your homepage, a product page, and your checkout. Note the scores.

On a recent client store, SAM Leisure back when it ran on WooCommerce, the pages were loading in around 3 to 5 seconds before I started. Without a baseline you cannot prove the changes helped, and you cannot spot if something quietly got worse.

Make sure you have a full backup too. On a shop, that is not optional.

The safe global options

The Perfmatters Options tab has a set of low-risk toggles that apply to the whole site. These are your easy wins.

Disable emojis. Disable embeds if you are not embedding external content. Turn off the WordPress dashicons on the front end if your theme does not use them for logged-out visitors. Clean up the WordPress head with the options for removing query strings and unnecessary meta.

None of these touch WooCommerce functionality. They just remove clutter that no store needs. Turn them on, then click through the site quickly to confirm nothing looks off.

The main event: the script manager

This is where the real speed comes from on WooCommerce, and it is also where you can break things, so slow down here.

The plan is simple to describe. Disable the WooCommerce scripts and styles everywhere, then switch them back on only for the pages that are part of the shop.

Open the Perfmatters script manager. You will see the WooCommerce scripts and styles listed, usually grouped so you can spot them. Set them to disabled everywhere as your starting point. That immediately stops them loading on your homepage, blog posts, and landing pages, which are the pages that never needed them.

Now re-enable them where they are needed. Using the current URL and post type conditions, switch the WooCommerce scripts back on for:

• The shop archive page
• Individual product pages (the product post type)
• The cart page
• The checkout page
• The my-account pages

Anywhere a customer touches products or their order, the scripts must load. Everywhere else they can stay off. On the client store above, this one change removed a large amount of unused JavaScript from the non-shop pages, and the homepage felt noticeably lighter straight away.

Do this in small steps and save often. After each meaningful change, test.

Cart fragments, handled carefully

WooCommerce uses an AJAX request called cart fragments to update the cart total without reloading the page. It runs on every page load by default, and on many sites it is one of the biggest single drags on performance.

Here is the nuance. If your theme shows a live mini-cart in the header that updates when someone adds a product, the site relies on cart fragments and you cannot simply switch it off everywhere without breaking that behaviour.

So the approach is to disable cart fragments on pages where there is no live cart total to update, and keep it where the theme genuinely needs it. Perfmatters gives you a specific option for the cart fragments script in the script manager. Disable it selectively, then add a product to your cart and watch the header. If the mini-cart still updates, you are fine. If it stops, re-enable it on the pages that need it.

Do not guess with this one. Test it directly.

Lazy loading without wrecking your LCP

Lazy loading tells the browser to hold off loading images until they are about to scroll into view. It saves bandwidth and speeds up the first paint, but there is a trap.

If you lazy load the image that sits at the top of the page, usually the main product image or a hero banner, you delay your Largest Contentful Paint and make your Core Web Vitals worse, not better. That is the opposite of what you want.

So enable lazy loading for images and iframes, then exclude the above-the-fold image. On product pages that means excluding the main product image while still lazy loading the gallery thumbnails and anything lower down. Perfmatters lets you add exclusions for exactly this.

Preloading the things that matter

Preloading tells the browser to fetch a critical asset early. Used sparingly, it helps. Used carelessly, it makes everything fight for bandwidth and slows the page.

On a WooCommerce store I preload two things: the main font the theme uses, and the hero or main product image on key templates. That is usually enough. Do not preload a long list of assets, because then nothing is prioritised.

Common mistakes that break checkout

I have cleaned up enough broken stores to know where people go wrong. Avoid these.

Disabling WooCommerce scripts on the cart, checkout, or account pages. This breaks the exact pages that take money. Always keep the scripts on there.

Turning off cart fragments globally when the theme has a live mini-cart. The cart stops updating and customers get confused. Disable it selectively and test the header.

Lazy loading the main product image. It tanks your Largest Contentful Paint and your scores drop. Exclude the above-the-fold image every time.

Making ten changes at once and only testing at the end. When something breaks you have no idea which change did it. Change one thing, test, then move on.

Assuming Perfmatters replaces caching. It does not. You still need caching set up to leave cart, checkout, and account pages uncached, or customers will see stale carts. Perfmatters and caching do different jobs.

Test checkout after every change

I will say it once more because it is the most important line in this guide. Place a real test order after every change. Add a product, go to the cart, proceed to checkout, and complete a test purchase.

Then click through the homepage, a blog post, and the account area. If anything fails, re-enable the last script you disabled, because that is nearly always the cause.

On SAM Leisure, once everything was tested and stable, the headline result was a load time down from around 3 to 5 seconds to roughly 0.3 seconds.

Pairing Perfmatters with the rest of your stack

Perfmatters is one layer. For the full picture, read my honest Perfmatters review covering how it performs across client sites generally.

Your host matters just as much on a shop, because checkout is dynamic and cannot be fully cached. My SiteGround vs Hostinger comparison covers the two hosts I get asked about most for WooCommerce. And if you are still weighing up the platform itself, my Shopify vs WooCommerce UK costs breakdown lays out what each one really costs to run.

Want this done for you?

Configuring Perfmatters on a live store without breaking checkout takes a careful hand, and not everyone wants to risk it on the site that pays their bills. If you would rather hand it over, speeding up WooCommerce stores is part of what my agency does day to day. You can find me at Glide Marketing.

Mike McDonnell, Founder of Glide Marketing