How to fix cwv lcp on Squarespace

Steps for Squarespace

1. Replace your hero/banner image with a WebP version: Pages → click your homepage → click the banner/header block → Edit → swap the image for a WebP file. Squarespace's CDN (powered by Fastly) serves images efficiently but uses the format you upload.
2. Keep the hero image file size under 500 KB before uploading: Squarespace does not allow direct control over preload tags without Custom Code injection.
3. Inject a preload hint: go to Settings → Advanced → Code Injection → paste into the Header field: <link rel='preload' as='image' href='YOUR-WEBP-IMAGE-URL' fetchpriority='high'>. Find the exact CDN URL by right-clicking the image on your live page → Copy Image Address.
4. Reduce render-blocking third-party scripts: Settings → Advanced → Code Injection → review any scripts in Header/Footer and move non-critical ones to the Footer field. Add 'defer' attribute to any script tags you control.
5. Disable unnecessary Squarespace extensions/plugins (Extensions → your installed extensions) that inject JS on every page load.
6. Verify with PageSpeed Insights. Note: Squarespace limits low-level performance tuning; if LCP remains above 2.5s after these steps, consider whether a platform with more control is appropriate for your business.

<link rel="preload" as="image" href="/images/hero-banner.webp" fetchpriority="high" imagesrcset="/images/hero-banner-800.webp 800w, /images/hero-banner-1500.webp 1500w" imagesizes="100vw">

<!-- Hero img tag — NO lazy loading, explicit dimensions -->
<img src="/images/hero-banner.webp"
     srcset="/images/hero-banner-800.webp 800w, /images/hero-banner-1500.webp 1500w"
     sizes="100vw"
     width="1500" height="600"
     alt="Descriptive hero text"
     fetchpriority="high"
     loading="eager">

What is cwv lcp?

Largest Contentful Paint (LCP) measures how long it takes for the biggest visible element on your page — almost always the hero image or headline banner — to fully appear on the screen after someone clicks your link. Google considers anything under 2.5 seconds "Good," 2.5–4 seconds "Needs Improvement," and over 4 seconds "Poor." An LCP of 7.5 seconds on mobile means shoppers are staring at a blank or half-loaded page for over seven seconds before they see your store's main content — a painfully long wait that drives them away before they ever see your products.

LCP is one of Google's Core Web Vitals, a confirmed ranking signal that directly affects where your store appears in search results. A poor LCP score suppresses organic traffic, meaning fewer potential buyers even find your store. On mobile — where most ecommerce browsing now happens — slow LCP dramatically increases bounce rates: studies consistently show conversions drop 4–8% for every additional second of load time. Improving LCP from 7.5s to under 2.5s can meaningfully lift both your search rankings and the percentage of visitors who stay long enough to make a purchase. Mobile-first indexing means Google judges your site primarily by its mobile experience, so a slow mobile LCP hurts your desktop rankings too.

See the complete Cwv lcp guide for every platform and the full background.