Shopify Speed Test: Is Your Store Fast Enough?
Slow Shopify stores lose customers. Test your store speed in 30 seconds - find out exactly what's slowing you down, which apps are the worst offenders, and how to fix it. Free, no account needed.
What We Check on Your Shopify Store
Core Web Vitals
LCP, CLS, FCP, and TTFB - the metrics Google uses to rank your store and that directly impact your conversion rate.
App Impact Analysis
We identify every third-party script on your store, measure its size and load time, and flag the apps slowing you down most.
Theme Performance
Liquid rendering time, CSS/JS bundle sizes, image optimisation, font loading, and render-blocking resources.
Why Your Shopify Store Is Slow
- 1Too many apps - each one injects JavaScript into every page, even pages where it's not needed
- 2Unoptimised hero images - large PNG/JPEG files instead of WebP, missing width/height attributes causing layout shift
- 3Heavy theme code - bloated Liquid templates, unused CSS/JS, render-blocking stylesheets
- 4Third-party scripts - analytics, chat widgets, pop-ups, and tracking pixels all competing for bandwidth
- 5No lazy loading - all images and videos load immediately instead of when the user scrolls to them
- 6Missing CDN optimisation - not leveraging Shopify's built-in CDN for image resizing and compression
Understanding Your Shopify Speed Score
Related Resources
Shopify Platform Scanner
Full Shopify-specific diagnostics with app bloat detection.
The Hidden Cost of Shopify Apps
How apps destroy your store speed - and which are the worst offenders.
How to Speed Up Your Shopify Store
Step-by-step guide to fixing Shopify performance issues.
Core Web Vitals for Ecommerce
What LCP, CLS, and FCP mean for your online store.
Frequently Asked Questions
How do I test my Shopify store speed?
Enter your Shopify store URL in the scanner above and click "Scan". PageDiag will analyse your store's Core Web Vitals, JavaScript payload, third-party scripts, and Shopify-specific performance factors. You'll get a detailed report with scores and fixes in under 60 seconds.
Why is my Shopify store so slow?
The most common causes of slow Shopify stores are: too many apps injecting JavaScript (the average slow store has 12+ apps), unoptimised images, heavy theme code, excessive third-party scripts (analytics, chat widgets, pop-ups), and Liquid rendering bottlenecks. Each installed app adds 200-800ms to your page load time.
Is my Shopify store fast enough?
A good Shopify store should load in under 3 seconds, with a Largest Contentful Paint (LCP) under 2.5 seconds and a Cumulative Layout Shift (CLS) under 0.1. If your Shopify speed score is below 50 on PageDiag, you're likely losing customers to slow load times.
Do Shopify apps slow down my store?
Yes - every Shopify app that touches your storefront injects JavaScript and often CSS into every page load. Even apps you've disabled but not uninstalled can leave residual code. Popular apps like Klaviyo, Loox, and Tidio can collectively add 2-4 seconds of load time. PageDiag identifies exactly which scripts are the heaviest.
How does Shopify speed affect sales?
Research from Deloitte shows that a 0.1-second improvement in load speed increases ecommerce conversions by 8.4%. For a Shopify store doing £10K/month, improving from a 5-second to a 3-second load time could mean an extra £1,000-2,000 in monthly revenue.
What is a good Shopify speed score?
On PageDiag, a score of 80+ is excellent, 50-79 needs improvement, and below 50 means you're losing significant revenue to slow load times. Note that Shopify's built-in speed score is relative to other Shopify stores - PageDiag measures absolute performance against Google's Core Web Vitals thresholds.
Ready to find out what's slowing your Shopify store?
Enter your URL above or scan from the homepage. Free scan, instant results, no account needed.