Why does my Shopify store still feel slow even after I removed apps I don't use?
Unoptimized images and script tags left behind by apps you uninstalled months ago are two of the most common, and most fixable, causes of a sluggish Shopify storefront.
What's going on
You uninstalled a handful of apps months ago, but your store still feels sluggish, and running it through a speed test shows a pile of render-blocking scripts and oversized images you don't remember adding. This is one of the most common complaints in Shopify merchant communities, and for good reason: it's really two separate problems wearing one trenchcoat.
The first is image bloat: product photos uploaded at full camera or supplier resolution, with no resizing or format optimization applied before they load on every product and collection page. The second is app residue: script tags, CSS, and snippets that apps inject into your theme, which don't always get removed automatically when you uninstall the app. Both slow down how quickly your page becomes visible and usable, and they compound. A theme carrying years of half-uninstalled apps plus unoptimized imagery can tank a speed score badly.
Why it happens
Installing an app that drops a script into your theme files is trivially easy, but uninstalling that app from your admin doesn't always remove the code it added. Apps built on Shopify's newer, more structured embed systems tend to clean themselves up when toggled off or removed, but older or more basic apps often hardcode their scripts directly into theme templates instead, and that code survives as inert but still-loading dead weight.
Image bloat happens for a simpler reason: Shopify's CDN can automatically resize and convert images to modern formats, but only when your theme's image tags actually specify a target size and format. Many themes, especially older or heavily customized ones, omit these settings, which means the full original file gets served on every page load instead of an optimized version, so the automatic optimization Shopify offers never actually gets used.
5 ways to fix it
Check your theme's speed report first so you're fixing the right thing
In Shopify admin, look under Online Store > Themes for the speed report link (it may also show up under Analytics > Reports). This gives you a 0-100 score built from real visitor data, plus Core Web Vitals, and it's the fastest way to see whether images, a specific app's script, or theme code is actually dragging you down before you start ripping things out blind.
Audit your installed apps and remove what you're not using
Go through your Apps section in admin and uninstall anything you're not actively using. Apps built on Shopify's newer app embed/app block system tend to clean up after themselves when removed, but older or more basic apps often hardcode script tags, snippets, and CSS directly into theme files, and that code can survive uninstall. After removing an app, check your theme's main layout and template files for leftover includes or stray script references tied to the app, and delete them by hand, or use a theme cleanup app if you'd rather not edit code yourself.
Make sure your product images are actually being optimized
Shopify's CDN can resize images and serve modern formats like WebP automatically, but only if your theme's image tags request it. If a template pulls an image without specifying a width or format, you often get the full-size original with no optimization applied. Check your product, collection, and homepage templates for image filters missing size and format parameters, and add them where they're missing. This is frequently the single biggest speed win available, since it's the difference between serving a multi-megabyte master file and a properly sized, modern-format image.
Confirm lazy loading and responsive images are actually working
Most current Shopify themes support lazy loading for below-the-fold images and responsive image sizing out of the box, so images that aren't visible yet shouldn't block your page from rendering. If you're on an older or heavily customized theme, verify this is actually happening by viewing the page source or inspecting a product page in your browser's dev tools. If it's missing, this is usually a free fix that doesn't require installing anything new.
For a thorough cleanup, bring in a developer
If your store has years of accumulated apps and custom code and you genuinely can't tell what belongs to what anymore, a one-time theme audit from a Shopify developer or agency is usually faster and safer than trial-and-error deletion, since they can trace code back to its source and confirm nothing breaks when it's removed.
Bottom line
Most of this is fixable without spending money: your theme's built-in speed report tells you where the time is actually going, and correctly sized, correctly formatted images plus a clean app uninstall process resolve the majority of slow-store complaints. The harder part is tracking down code left behind by apps you removed a while ago, which is more of a search-and-verify task. A theme audit, whether you do it yourself file by file or hire it out, is the way through that.
Browse the rest of the problem library, run a free storefront scan to catch issues like this automatically, or email us and we'll work out a custom solution for it.