A slow store costs you in two ways. First, visitors leave before the page finishes loading — Google found that the probability of bounce increases 32% when load time goes from 1 second to 3 seconds. Second, Google uses page speed as a ranking signal, so slow stores get less organic search traffic.
The good news is that most Shopify speed problems are fixable without a developer. The bad news is that many merchants have no idea their store is slow until they run a test.
Start here: go to PageSpeed Insights and enter your store URL. Run it on mobile, not desktop. Mobile scores are almost always lower and are what Google primarily uses for ranking.
If your mobile score is below 50, you have a real problem. 50–70 is average. 70+ is where you want to be.
The biggest speed killers on Shopify stores
Too many apps injecting scripts
Every app you install has the potential to load JavaScript on your storefront. Some apps load their scripts on every page, even pages where they're not doing anything. If you have 15 apps installed, you might have 12 extra script files loading on every page load.
Go to your Shopify admin and look at your installed apps. For each one, ask: is this app actively contributing to my store's performance, or is it something I installed and forgot about? Uninstall anything you're not actively using.
For apps you want to keep, check if they have a setting to load only on specific pages. A chat widget doesn't need to load on your checkout page. A upsell app doesn't need to load on your blog.
Uncompressed, oversized images
This is the most common speed problem on Shopify stores and the easiest to fix. Images that are 4MB each are the default when you upload from a phone or camera — and they're completely unnecessary for a web store.
Shopify does compress and resize images automatically when it serves them, but only if you've given it high-quality originals to work with. The issue is usually the number of images loading on a page, not just their individual size.
For product images, 2000px on the longest side at 80% JPEG quality is plenty. You don't need 6000px raw files. Tools like Squoosh (free, browser-based) let you batch compress images before uploading.
Autoplay videos on the homepage
Video backgrounds and hero videos look good in a theme demo. In practice, they're often the biggest single contributor to slow homepage load times — especially on mobile where connections are slower and memory is limited.
If you use a video on your homepage, make sure it's hosted properly (Shopify CDN or a video service like Vimeo) rather than self-hosted, and that it has a static image fallback that loads while the video is fetching. Autoplay video that blocks page rendering is a significant performance problem.
There are ways to use video backgrounds without hurting performance — lazy loading, proper compression, serving WebM format to supported browsers — but they require either good app support or a developer.
Fonts loading from external sources
Custom fonts are great for branding. But if your theme loads 6 font weights from Google Fonts (or worse, a slower font CDN), each of those is a separate network request that can delay your page rendering.
Most themes use more font weights than they need. If your theme is loading thin, light, regular, medium, semibold, and bold variants of a font, chances are your store only uses three of them. This is a theme code change, but it's worth flagging to a developer if you ever do any theme work.
The Shopify app badge and other third-party scripts
Marketing pixels (Meta, TikTok, Google Ads), review widgets, live chat tools, pop-up apps — every third-party script that loads on your storefront adds to your load time. Some of them are unavoidable if you're running paid advertising. Others can be deferred or loaded after the page is interactive.
Check which tracking pixels you actually need versus ones you set up during a campaign that's long over.
What Core Web Vitals actually measure
PageSpeed Insights reports three Core Web Vitals that Google uses as ranking signals:
LCP (Largest Contentful Paint) — how long it takes for the biggest visible element on the page to load. Usually your hero image or video. Under 2.5 seconds is good. This is the one that matters most for Shopify stores.
CLS (Cumulative Layout Shift) — how much the page visually shifts while loading. If elements jump around as images and fonts load in, that's a high CLS score. Under 0.1 is good. Common cause on Shopify: images without defined width and height attributes.
INP (Interaction to Next Paint) — how quickly the page responds to user input (clicks, taps). Under 200ms is good. Heavy JavaScript is usually the culprit when this is slow.
Of the three, LCP is the one most Shopify merchants can directly impact without code changes — primarily by improving image sizes and reducing the number of scripts that block page rendering.
Quick wins to try today
- Run the PageSpeed test and note your score and the top three recommendations.
- Uninstall unused apps — any app you haven't actively used in 30 days.
- Check your homepage hero image — if it's a JPEG larger than 500KB, compress it.
- Review your video settings — if you have a homepage video, check that it has a static fallback image.
- Count your active tracking pixels — remove any for ad platforms you're no longer running.
Speed optimization has diminishing returns as you get further into it, but the first few fixes tend to have the most impact. Getting from a 35 mobile score to a 55 is usually achievable without any code changes. Getting from 55 to 80 typically requires theme-level work.
Start with the easy stuff and measure the improvement before going further.
