Shopify Speed Optimization: Fixes That Work
How to read Shopify’s speed report, what good Core Web Vitals scores look like, and the image, app and script fixes Shopify rates as high impact.
Start with Shopify’s own speed report, which uses visits from your real customers. Most of the fixes that follow come down to the main image, your apps and how scripts load.
Read your speed report first
Shopify’s web performance reports show your store’s three Core Web Vitals, the speed and stability measures Google publishes. Filter by device and page type, because a slow product page on mobile can hide behind a healthy store average.
| Measure | What it tracks | Good | Poor |
|---|---|---|---|
| LCP | How fast the main content loads | 2.5 seconds or less | Over 4 seconds |
| INP | How fast the page responds to taps | 200 ms or less | Over 500 ms |
| CLS | How much the layout jumps | 0.1 or less | 0.25 or more |
The report can show app installs and theme changes on its timeline, so check what changed around any sudden drop. Data can lag by up to 36 hours, so give a fix a few days before you judge it.
Fix the main image
These come from Shopify’s theme performance guidance, which rates the first four as high impact.
- Never lazy-load the largest image at the top of the page
- Give that image fetchpriority="high"
- Do not hide it behind an animation
- Use a real image tag for it, not a CSS background
- Serve correctly sized images, with width and height set so the page does not jump
Audit your apps and scripts
Every app, tracking pixel and theme script has a cost. Shopify’s advice is to remove anything that isn’t earning that cost, starting with apps that block the page from rendering. Removing an app may leave code behind in your theme, so check after you uninstall. Our Shopify app audit guide gives you a way to review them.
- Add defer or async to scripts that are not critical
- Load widgets such as chat when someone first interacts, not on page load
- Render essential content in Liquid and HTML so it does not wait for JavaScript
- Reserve space for app content so it does not push the page down
Be careful with speed apps and scores
Shopify’s guidance warns about fake performance apps, so judge any app by your real-customer report, not by a test score alone. A lab score is useful for spotting problems, but it isn’t the experience your customers get. For reference, Shopify’s Theme Store asks for an average Lighthouse score of at least 60.
If the report stays poor after this, the theme itself may need work. Our commerce audit and Shopify development service cover that, and our Shopify CRO guide covers what to test once the store is fast.
