Free tool for Shopify

Free Shopify speed test

Is your Shopify store slow on phones? Enter your store URL, or a product page, to run a mobile Google Lighthouse test. In about a minute you get your score, LCP, CLS and TBT, plus the top 3 fixes in plain English. No signup, no app.

Free. Up to 5 checks per hour. Takes about 20 to 40 seconds.

Why Shopify stores get slow

Shopify hosting is fast. What slows a store down is what gets added on top of it: apps, theme code, tags and heavy media.

1. Apps that inject scripts

Reviews, upsells, wishlists, popups, chat and loyalty apps add their own JavaScript and CSS to the storefront, often on every page. Code from apps you removed can stay behind in the theme, still loading on every visit. Check the app embeds in the theme editor, remove leftover snippets from old apps, and load chat and popups after the shopper interacts.

2. Theme JavaScript

Slideshows, mega menus, quick view, sticky headers and scroll animations all run code while the page loads, and older themes may load jQuery for small effects. This shows up as a high TBT and a store that feels sluggish to tap. Defer theme scripts that are not needed for the first screen and remove sections you do not use.

3. Tags and tracking pixels

Google Tag Manager, GA4, Meta, TikTok, Pinterest, Klaviyo and heatmap tools each load more scripts. Inside Tag Manager it is easy to keep tags for campaigns that ended long ago. Remove dead tags, delay the ones that do not need to fire on load, and consider moving pixels to Shopify's Customer Events, which runs them in a sandbox away from the main page.

4. Images and hero video

A full-width slideshow with several large images, or an autoplay video at the top of the homepage, is the most common reason for a slow LCP on Shopify. Shopify's CDN can serve resized WebP or AVIF files when the theme asks for the right widths, but custom sections often request one large file for every screen. Use a single hero image sized for phones, give videos a poster image, and do not lazy-load the hero.

5. Platform code you cannot remove

Every Shopify store loads some platform scripts, such as analytics and Shop Pay. That sets a ceiling on how high a mobile score can go, which is why you should compare against your own starting numbers rather than chase a perfect 100.

Reading your Shopify results

LCP (good: under 2.5 s): On most stores this is the hero image, slideshow or main product photo. A slow LCP usually means that image is too large, lazy-loaded, or waiting behind scripts.
CLS (good: under 0.1): Layout jumps on Shopify often come from announcement bars, review stars and badges that apps insert after load, and fonts that swap late. Reserve space for those elements.
TBT and INP (good: under 200 ms): INP measures how quickly the store reacts when real shoppers tap, such as opening the menu or adding to cart. The lab test reports TBT, the time scripts keep the page frozen. On Shopify, apps and tags are the usual cause.
The score: A weighted blend of the lab metrics, from 0 to 100. Because of platform code and the apps a store needs, track your own before and after numbers, and focus on LCP, CLS and TBT rather than the headline score.

Tip: before changing anything, duplicate your live theme and make edits there. Run this test on the theme preview and on the live store to compare.

Want it fixed for you?

Shopify Speed Fix: $597 for the theme fix (images, hero media, LCP and theme scripts) or $997 for the theme plus app and tag deferral, done on a duplicate theme with your approval and a before and after report.

Shopify Speed Fix has no score guarantee. After the free report I quote a conservative target for your store and only promise the work in scope.

See Shopify Speed Fix

Questions

Is the Shopify speed test free?

Yes. No signup and no app to install. A fix plan by email is optional and also free.

Which page of my store should I test?

Start with the homepage, then test your best-selling product page and a main collection page. They load different sections and apps, so they often have different problems. Shoppers from ads and search usually land on product pages.

Why is my score low when the store feels fast on my phone?

Your own phone is likely fast, on Wi-Fi and has the store cached. The test simulates a mid-range phone on slow 4G with an empty cache, which is closer to a new shopper arriving from an ad.

Will removing apps speed up my Shopify store?

Often, yes, especially apps that load on every page. After uninstalling, check the theme for leftover code, because some apps leave snippets behind. Duplicate the theme before editing so you can switch back.

Is this the same as the speed numbers in my Shopify admin?

No. Shopify's web performance report shows Core Web Vitals (LCP, INP and CLS) from real shoppers over time. This test is a single lab run on one page, which makes it better for finding causes and checking a change right away.

Do you guarantee a score after the Shopify Speed Fix?

No. Shopify Speed Fix has no score guarantee. Platform code, checkout scripts and the apps you keep all limit what any theme fix can reach, so after the free report I quote a conservative target for your store and only promise the work in scope.

Running WordPress instead? Try the WordPress speed test. Any other site: free website speed check.