How to fix cwv cls on Squarespace

Steps for Squarespace

1. Images: Squarespace's image blocks automatically generate width/height attributes in modern templates (7.1). If you are on a 7.0 template, migrate to a 7.1 template to get this benefit automatically.
2. Banners / announcement bars: In Pages → Not Linked → promotional pop-ups, or in the Announcement Bar settings, set position to 'bottom' or use a modal overlay style to avoid pushing page content down.
3. Custom code embeds: Go to any page → Edit → Add Block → Code, and wrap third-party scripts (reviews, chat, social) in a <div style='min-height:150px'> so space is reserved. Enter this in Settings → Advanced → Code Injection (site-wide).
4. Fonts: In Design → Fonts, choose from Squarespace's curated list; these are loaded with optimised settings. For custom fonts added via Code Injection → CSS, add font-display: swap; inside your @font-face rule in Settings → Advanced → Code Injection → CSS.
5. Header scripts: Any JavaScript injected via Settings → Advanced → Code Injection → Header that modifies layout should be deferred with defer or async attribute to prevent shifts during initial load.
6. Verify: Run PageSpeed Insights on your Squarespace domain; CLS should be < 0.1.

What is cwv cls?

Cumulative Layout Shift (CLS) measures how much page content unexpectedly moves around while a visitor is looking at it. Every time an image pops in and shoves text down, a banner slides in from a cookie notice, or a font swap causes a paragraph to reflow, that counts as a layout shift. Google adds all those shifts together into a single score; anything above 0.1 is considered "needs improvement," and above 0.25 is "poor." A score of 1.35 (like the example above) means the page is shifting dramatically — visitors are misclicking, losing their place, and bouncing before they buy.

CLS is one of Google's three Core Web Vitals and is a direct ranking signal in Google Search — a poor score actively suppresses your position in search results, reducing organic traffic and revenue. On mobile, where most ecommerce shopping happens, layout shifts are especially jarring: a customer tapping "Add to Cart" can accidentally tap a shifted link instead, killing the conversion. High CLS also signals a low-quality page experience, which increases bounce rate and reduces the trust visitors place in your store. Google's own data shows that sites meeting Core Web Vitals thresholds see measurably better business outcomes than those that don't.

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