How to fix low performance score on Squarespace

Steps for Squarespace

1. Squarespace hosts all sites on its CDN with GZIP automatically — focus on what you control: content and third-party code.
2. Optimise images before uploading: resize to the largest display size needed (max ~2000 px wide) and compress with Squoosh to WebP under 200 KB. Squarespace resizes on the fly but starts from your uploaded file.
3. Avoid embedding heavy third-party iframes (YouTube embeds load a large JS bundle) — use a lite-embed approach: Pages → Edit → replace standard YouTube blocks with a linked thumbnail image.
4. Remove unused Code Injection: Settings → Advanced → Code Injection — delete any old analytics, chat, or pixel scripts you no longer use.
5. Minimise custom fonts: Design → Fonts — each additional font family adds an external HTTP request; limit to 2 families total.
6. Disable or limit Squarespace Fluid Engine animations and parallax effects on product/category pages — these contribute to CLS and INP on mobile.
7. Re-test with PageSpeed Insights; note that Squarespace's platform constraints mean scores above 70–80 mobile are hard to achieve without migrating to a more flexible platform.

What is low performance score?

The Lighthouse Performance Score (shown in Google's PageSpeed Insights tool) is a single number from 0–100 that summarises how fast your web page loads and responds for real users — especially on mobile. It is calculated from five timing metrics, with the three Core Web Vitals (Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift) carrying the most weight. A score below 50 is considered "Poor" by Google; a score above 90 is "Good." Think of it as a health-check report card for your page's speed: every point you gain means real customers are waiting less and leaving less.

Google officially uses page experience signals — including Core Web Vitals — as a ranking factor, meaning a very low score can directly suppress your position in search results and reduce organic traffic. Beyond rankings, a slow page destroys conversions: industry data consistently shows that each additional second of load time drops conversion rates by 10–20 %, and mobile shoppers are the most sensitive. A score of 8/100 on mobile means the vast majority of your mobile visitors are likely bouncing before they even see your products, costing you both ad spend and organic sales. Closing this gap is one of the highest-ROI technical improvements an ecommerce store can make.

See the complete Low performance score guide for every platform and the full background.