Images, videos, slideshows, chat widgets, and apps—adding them can make your Shopify store seem more useful. But more features don't always mean a better experience. As those resources pile up, pages take longer to appear, leaving you with more work when you tackle Shopify store speed optimization.
You try to find effective Shopify store speed optimization strategies to improve the situation. Image compression may seem like an obvious first step, but overdoing it can leave your images blurry without noticeably improving your store’s speed. If downsizing your images doesn’t help much, what’s really slowing down your store?
This guide covers how to measure your store's performance, find the cause of the slowdown, and fix it. By the end, you’ll know what to work on first and how to see if your changes make things better for shoppers.
Before You Start
Is your Shopify store actually slow? Are there specific metrics to measure its performance? And why is speed optimization so important? These are essential questions to answer before you move on to speed optimization. Doing so will help you assess your store’s speed and lay a foundation for subsequent optimization.
What does a slow Shopify store feel like to shoppers?
When browsing your online store, shoppers will find it slow if they encounter any of the following issues:
-
Key content appears late: Shoppers see a blank or incomplete page when they enter your store. Even when the basic layout is visible, the key elements, such as product images, are still loading.
-
Delayed interactions: When a shopper opens a menu, selects a product choice or adds an item to their cart, they have to wait for the page to reply. The cart is also slow to update quantity changes, apply discounts, and calculate the total again.
-
Scrolling feels choppy: Shoppers experience occasional stalls when browsing down the page. When using a mobile device, the issue could be more apparent than when using a desktop computer to access the store.
Understanding Core Web Vitals
Apart from shoppers’ experience, three metrics help evaluate your site performance. Core Web Vitals turn the general feeling that a store is “slow” into three measurable metrics: LCP, INP, and CLS.
-
Largest Contentful Paint (LCP) measures when the largest visible image or text block appears—above 2.5 seconds signals slower loading, and above 4 seconds means Poor.
-
Interaction to Next Paint (INP) tells you how quickly a page responds after a shopper clicks or types. An INP above 200 milliseconds indicates a delay; once it exceeds 500 milliseconds, the rating drops to Poor.
-
Cumulative Layout Shift (CLS) measures unexpected movement on the page. A CLS score above 0.1 is unstable; above 0.25 is Poor.
Why Shopify store speed matters
Getting shoppers to your Shopify store through search engines, social media, and referrals takes a lot of work. But it means nothing if shoppers end up leaving. When product images appear late, filters respond slowly, or Add to Cart lags, most people leave before getting to know your products, while many others abandon a purchase they had already started.
A tenth of a second may not sound like much. But in Shopify’s analysis, every extra 0.1s of LCP was associated with about 3.5% lower conversion. Faster pages give more shoppers a chance to see key content, interact with the store, and complete their purchase.
How to Identify Shopify Speed Issues
Now that we’ve covered the basics, let’s get to work. We’ll use Shopify’s built-in Web Performance reports as well as Google’s PageSpeed Insights.
Review your Shopify Web Performance reports
Shopify’s reports show you which Core Web Vital needs attention and whether the issue affects a page type or a specific URL.
In your Shopify admin, open the Online Store. The summary at the top rates LCP, INP, and CLS as Good, Moderate, or Poor. Choose a metric marked Moderate or Poor to investigate first.
To find its Over Time, Page Type, and Page URL reports, open Analytics > Reports and enter a colon (:) in Search reports. For the metric you selected, review the following reports:
Shopify creates these reports based on real store visits. Start your review with two questions:
-
Which metric needs attention?
-
Start with LCP, INP, or CLS marked Moderate or Poor.
-
Where does the problem show up?
-
Start with Page Type: See whether the issue affects product pages, collection pages, the homepage, or another page type.
-
Next, check Page URL: If several URLs have the same problem, look for what they have in common, such as a template or app. If only one URL is slow, check the images, videos, and sections on that page.
-
Compare mobile and desktop results: Use the Device type filter to compare the same URLs on the Page URL report.
Use the checklist below to record the key details from Shopify’s Web Performance reports. Note the affected Core Web Vital, page type, URLs, and device. This will help you decide which URL and device to test next in PageSpeed Insights.
Test pages with Google PageSpeed Insights
Open PageSpeed Insights (PSI) and start by testing the affected URLs in your checklist to evaluate page speed and loading speed for each one. If Shopify does not identify a specific URL, test the homepage, a high-traffic collection page, and a typical product page separately.
After testing each URL, review the PageSpeed Insights report in two stages:
1. Check the Core Web Vitals.
Start with field data, which shows how real shoppers experienced the page. Note any LCP, INP, or CLS result marked Needs Improvement or Poor.
Note: Check whether the data is for This URL or Origin. Origin data covers many pages across the store, not only the URL you tested. If no field data appears, the page may not have enough visits.
2. Check the issues found by PageSpeed Insights. Go to Insights and Diagnostics.
Look for problems such as:
-
Improve image delivery
-
Render-blocking requests
-
Serve images in next-gen formats
-
Font display
-
LCP request discovery
-
Unused JavaScript
-
Third-party code from apps, trackers, or widgets
These diagnostics help pinpoint website speed problems on a Shopif y site.
What the metrics reveal
Now that you’ve reviewed the reports, do all those scores and red flags leave you wondering what to do next? Each one offers a clue about what’s slowing your store down.
-
Poor LCP can come from:
-
The hero image is too large.
-
The main image starts loading too late.
-
CSS, JavaScript, or a slow server response delays the main content.
-
Poor INP can come from:
-
Apps, trackers, or widgets load too much JavaScript.
-
Heavy theme code keeps the browser busy.
-
A click starts too much work before the page can respond.
-
Poor CLS can come from:
-
Images, videos, or app embeds do not have space set aside for them.
-
Fonts, animations, or theme elements change the size of the content.
Practical ways to improve your store’s performance
Before we get into the fixes, one quick reminder: make changes in a duplicate theme, not the live version. This way, even if a problem arises, your live version will still function correctly. Once you’ve tested the changes and everything works as expected, you can publish the updated theme.
Optimize images and media
Is your LCP rated Poor, or has PSI flagged an image delivery issue? Start with the fixes below.
-
Resize and compress large hero and product images as part of image optimization. Correct image size before upload, avoid oversized images for hero and product media, and remember that Shopify automatically compresses JPG images using advanced algorithms, but you still need properly sized files. An image optimizer can help with bulk cleanup, and responsive images ensure appropriate sizes for mobile devices and desktop screens.
-
Load the LCP image first so shoppers can see and use the page sooner.
-
Lazy-load off-screen media. Apply lazy loading to images and iframes farther down the page, and use Shopify's image CDN to resize assets with Liquid filters. For video embeds, show a poster image first and load the full player after a shopper clicks.
-
Remove unnecessary sliders, GIFs, and autoplay videos.
Remove unused Shopify apps
If your INP is rated Poor, or PSI flags too much JavaScript or third-party code, check the apps you’ve installed.
-
Remove duplicate or unnecessary apps: If you installed several apps to compare the same feature, remove the ones you did not choose. Keeping fewer apps means the storefront has fewer scripts and stylesheets to load.
-
Uninstall unused apps thoroughly: According to Shopify, some apps leave code in your Shopify theme after uninstalling. Follow the app’s instructions or ask the app developer whether any extra cleanup is needed.
-
Test affected features: After removing an app, check any features associated with it, such as reviews, search, recommendations, and checkout.
Reduce third-party scripts
Analytics tools, tracking pixels, chat widgets, and app embeds all add third-party code to your store. Too much JavaScript slows page loading and delays user interaction.
Take the steps below when your INP or LCP is rated Poor, or PSI flags third-party code or unused JavaScript.
-
Review and remove unnecessary scripts: Note what each script does and where it loads. Remove tags from old campaigns, finished tests, and tools that collect the same data.
-
Control when and where scripts load: Load each widget or tag only on pages that need it. Delay chat widgets and video players until the main content loads or a shopper opens them. Ask a developer before changing analytics, tracking, or consent scripts to avoid losing data or disrupting consent controls.
-
Test tracking after changes: Confirm that analytics events, advertising pixels, consent controls, and conversion tracking still work.
Optimize theme code
Seeing render-blocking files, unused CSS, and heavy JavaScript in PSI? You can follow the steps below to fix these issues.
-
Load code only where needed: Keep gallery code on product page templates instead of loading it on collection pages or blog posts.
-
Prioritize critical CSS: Load the styles needed for above-the-fold content right away. Defer non-critical CSS and JavaScript until later.
-
Use Shopify’s CDN: Optimize fonts and theme assets. Keep only the web font files your store uses. Store CSS, JavaScript, and fonts in the theme assets so Shopify can deliver them through its content delivery network.
-
Check Liquid rendering: If server response is slow, use Shopify Theme Inspector for Chrome to find nested loops or repeated work.
Prevent layout shifts
Do images, banners, or buttons jump while the page loads? That raises CLS and can make shoppers tap the wrong place.
-
Reserve space for media: Add width and height values or an aspect ratio to images, videos, and iframes.
-
Make room for late content: Set aside space for review widgets, app blocks, and promotional banners before they appear.
-
Check mobile and desktop layouts: Review product galleries, embedded videos, and app content on mobile devices and desktop PCs.
Shopify Speed Improvements You Can Make Without a Developer
Improving your Shopify store speed does not always require coding skills or a development team. Start with a few high-impact tasks that you can handle by using Shopify admin or the right speed optimizer.
-
Optimize images: Resize images before uploading them, compress large files, and use modern formats such as WebP. Avoid unnecessary sliders, GIFs, and autoplay videos, especially on mobile pages.
-
Review installed apps: Remove apps you no longer use or those with overlapping functions. If you are concerned about leftover code or unexpected effects, contact the app developer and ask them to help remove the app safely.
-
Try SEOWILL: Tired of checking for speed issues after every store update? SEOWILL gives you an easier way. It helps you identify areas for improvement and reduce repetitive manual work, even if you are not a technical expert.
Final Words
By now, you should know where to start. Follow the steps in this guide and work through the problems one by one. Every fix makes your Shopify store a little faster.
Remember that speed optimization isn’t a one-time job. Your content will change, you may install new apps. Today’s improvements may not last. Recheck your performance data after making modifications and fix any further issues you discover. Keep at it, and your store might get speedier over time, with a better possibility of converting more shoppers.
FAQ about Shopify Speed Optimization
Why is my Shopify store slow, and what should I check first?
Slow stores are typically caused by unoptimized images, excessive use of apps, bloated theme code, or too many third-party scripts.
You can start by using Shopify’s Web Performance reports to assess the affected devices, Core Web Vitals, page types, and specific URLs. Then, test these pages using PageSpeed Insights. Focus your review on issues such as theme code, the number of installed apps, tracking tags, large images and videos, and the number of page sections.
Why is my Shopify store slow on mobile but fast on desktop?
This is common, and there are usually two reasons for it.
First, if you are comparing scores across PageSpeed Insights, remember that the mobile and desktop tests run in different settings. According to Google, the mobile test simulates a mid-range phone on a mobile network, whereas the desktop test uses an emulated desktop with a wired connection. Therefore, the mobile score tends to be lower. That doesn’t always indicate there’s something wrong with Shopify or your store. So you don’t have to go after a perfect score.
Second, if your customers find your store slow on mobile, it is probably because their phone’s processor and network connection make existing performance issues worse. To know what causes the lag, filter Shopify’s Web Performance data by mobile device. This allows you to see which pages and metrics are underperforming. Then, use PageSpeed Insights to test those pages, find the cause, and make targeted fixes.
Why do Shopify and Google PageSpeed Insights show different results?
Shopify and Google PageSpeed Insights use different visitor samples and time periods. Shopify’s reports include visits from Chromium-based browsers and Firefox. PSI’s field data comes from opted-in Chrome users over the past 28 days, while Lighthouse runs a simulated test of one URL.
