Core Web Vitals are Google's measures of how a page feels to a real visitor. Three matter: LCP (how fast the main content appears), INP (how quickly the page responds to taps and clicks) and CLS (how much the layout jumps around). Google's published "good" thresholds are an LCP of 2.5 seconds or less, an INP of 200 milliseconds or less and a CLS of 0.1 or less.
Measure the right thing first
A single lab test score can swing between runs. Look at real-visitor data where it exists: the Core Web Vitals report in Google Search Console, and the field data section of PageSpeed Insights. Use lab tests to find causes, not to declare victory.
1. Fix the biggest image first (LCP)
On most Shopify pages the largest element is a hero or product image. Make sure it is properly sized, in a modern format and not lazy-loaded when it sits at the top of the page. Lazy-load images further down.
2. Audit your apps (LCP and INP)
Every app can add scripts that run on every page. Remove apps you no longer use, and check that uninstalled apps have not left code behind in your theme. This is often the single biggest win on an older store.
3. Reserve space for things that load late (CLS)
Give images, banners, embedded widgets and announcement bars fixed dimensions so the page does not shift when they appear. Pop-ups and review widgets are common offenders.
4. Trim theme JavaScript and CSS (INP)
Heavy sliders, animation libraries and tracking scripts slow down the page's response to a tap. Delay or remove what you do not need, and load non-essential scripts after the page is usable.
5. Handle fonts sensibly
Limit the number of font families and weights, and use font-display: swap so text shows immediately instead of staying invisible.
Retest, then keep watching
Field data takes a few weeks to reflect changes, so do not panic if the report does not move straight away. Check again after 28 days.
Want it done properly?
Our Shopify speed optimization service audits apps, scripts, images and theme code, and measures the result against real visitor data. For more tips, read how to speed up your Shopify store.
Related services
- Shopify Site Speed & Performance Optimization – an audit of apps, scripts, images and theme code
- Shopify Product Image Editing & Optimization – clean, compressed product photos with alt text
- Custom Shopify Section & Feature Development – custom sections you can edit in the theme editor
