How to fix low performance score on Squarespace
Improve your Lighthouse/PageSpeed performance score by reducing page weight, deferring JavaScript, optimizing images, and fixing Core Web Vitals metrics so your store loads fast on mobile and desktop.
Steps for Squarespace
- Images — In the Pages panel, edit each page and click every image block → Image Settings → set focal point; Squarespace auto-serves WebP and resizes via its CDN when you upload correctly-sized originals (keep source files under 500 KB and no wider than 2500 px).
- Remove third-party scripts — Settings → Advanced → Code Injection: audit the <head> and footer code blocks. Remove any unused analytics, chat, or marketing scripts.
- Fonts — Design → Fonts: limit your selection to 1–2 font families; each additional font family adds an external request. Use system fonts (e.g., '-apple-system, sans-serif') via custom CSS for body text if performance is critical.
- Page sections — Edit each page and delete or hide any sections/blocks that are not visible or not needed; hidden blocks still load their assets in some Squarespace versions.
- Commerce scripts — Extensions → (review): uninstall any Squarespace Extensions that inject scripts if you are not actively using them.
- Video — Replace background videos on mobile by going to the section settings and toggling 'Disable video on mobile' — this alone dramatically improves mobile LCP.
<!-- Hero/LCP image: load eagerly with high priority, explicit dimensions -->
<img
src="hero-banner.webp"
alt="Summer collection — shop now"
width="1200"
height="600"
loading="eager"
fetchpriority="high"
/>
<!-- All below-fold images: lazy-load, explicit dimensions to prevent CLS -->
<img
src="product-thumbnail.webp"
alt="Blue running shoes"
width="400"
height="400"
loading="lazy"
/>
<!-- Defer non-critical third-party scripts -->
<script src="https://example-chat-widget.com/widget.js" defer></script>What is low performance score?
Lighthouse (the engine behind Google's PageSpeed Insights tool) grades every page from 0–100 on performance. The score rolls up several real-world loading metrics — most importantly Google's Core Web Vitals: Largest Contentful Paint (LCP, how fast the main content appears), Interaction to Next Paint (INP, how fast the page reacts to taps/clicks), and Cumulative Layout Shift (CLS, how much the layout jumps around). A score of 8/100 on mobile means the page is extremely slow for the majority of shoppers who visit on a phone. The score is not a vanity number — it reflects a genuine, measurable delay that real visitors experience.
Google uses page experience signals, including Core Web Vitals, as a ranking factor for mobile search — a store with a very low score can lose meaningful search visibility to faster competitors. Beyond rankings, conversion research consistently shows that every additional second of load time can reduce conversions by 10–20%; a score in single digits means customers are likely abandoning the page before it even finishes loading. Slow pages also penalize your Google Ads Quality Score, raising your cost-per-click. On mobile — where most ecommerce traffic now originates — the experience gap between a score of 8 and 80 is the difference between a bounce and a sale.
See the complete Low performance score guide for every platform and the full background.
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