UK buy-now-pay-later scripts
Klarna and Clearpay are near-universal on UK Shopify stores. Both inject JavaScript on every product page regardless of whether the customer uses them, adding 200–600ms to LCP and blocking the main thread.
UK Service
Shopify Speed Optimisation for UK Stores
UK Shopify stores commonly install Klarna, Clearpay, Trustpilot, and Klaviyo — each injecting scripts that slow your theme score and Core Web Vitals. We audit, prioritise, and fix the issues that matter for UK shoppers and Google UK rankings.
Why UK Shopify sites are slow
UK stores face a specific set of performance problems that generic guides rarely address — payment gateways, GDPR scripts, and UK-specific app ecosystems.
UK review and UGC platforms
Okendo, Stamped, Trustpilot, and Reviews.io each load separate scripts and widget code on every product page. UK stores frequently install two or three of these simultaneously, compounding the overhead.
GDPR consent banner loading
UK stores must present a GDPR-compliant cookie banner before setting non-essential cookies. CookieYes, OneTrust, and similar tools load scripts that cause layout shift and delay rendering if not configured carefully.
UK email and SMS marketing tools
Klaviyo, Dotdigital, and Omnisend — popular with UK merchants — each add tracking scripts to every storefront page. Klaviyo alone can add 300–500ms when loaded synchronously.
Theme section bloat from Shopify 2.0
Shopify 2.0 themes give UK merchants flexibility to add sections, but each section typically adds its own CSS and JavaScript. Stores with 8–12 active homepage sections regularly score under 40 on mobile.
Currency and international pricing apps
UK stores selling internationally use currency conversion apps that inject scripts to detect location and reformat prices. These run on every page load and frequently block rendering.
What we fix
Every fix is prioritised by measured impact — we address the issues that move the needle most for UK Shopify stores.
Theme PageSpeed score
We audit the theme on a clean version with apps disabled to establish a baseline, then isolate which apps and customisations are responsible for the score drop.
Conditional app script loading
BNPL scripts (Klarna, Clearpay) are loaded only on product, cart, and checkout pages rather than site-wide. Review widget scripts are deferred so they do not block the initial render.
LCP on product pages
Product hero images — the most common LCP element on Shopify stores — are converted to WebP, given correct dimensions, and preloaded so the browser prioritises them immediately.
Core Web Vitals in Search Console
We target the three metrics Google uses as ranking signals: LCP under 2.5 seconds, INP under 200ms, and CLS under 0.1. Each is measured before and after using both lab and field data.
GDPR consent banner CLS
Space is reserved for the consent banner before it loads so it does not push page content down on appearance, eliminating the CLS contribution that most consent implementations cause.
Shopify Markets and international scripts
Currency and geolocation scripts are audited and either deferred or replaced with lighter alternatives that do not block the critical rendering path.
How it works
- 1
Free audit
Run your site through Loadzen to get a baseline score and Core Web Vitals reading. We identify the highest-impact issues before any work begins.
- 2
Prioritised fix plan
We produce a prioritised list of changes ordered by impact. You see exactly what will be done and why before we start.
- 3
Implement and verify
Fixes are applied and measured. We verify scores improve in both lab data and, over 28 days, in Google Search Console field data.
Frequently asked questions
- Do you optimise Shopify stores specifically for UK search rankings?
- Yes. Google's UK search results use the same Core Web Vitals ranking signals as elsewhere, but UK Shopify stores have a specific set of app and integration patterns that affect performance. We are familiar with the UK app ecosystem and address the issues that are most common for UK merchants.
- Can you reduce the performance impact of Klarna and Clearpay on my Shopify store?
- Yes. Both Klarna and Clearpay load JavaScript on every product page by default. We configure their scripts to load conditionally — only on the pages where the BNPL option is shown — which removes the overhead from the rest of the store without affecting the checkout experience.
- Will speed improvements affect my Shopify theme's appearance?
- No. We do not modify the visual design or layout of the theme. Changes are limited to how and when assets load, image formats, and script execution order. The store looks and behaves identically — it just loads faster.
- What is a realistic Shopify PageSpeed score for a UK store?
- Most UK Shopify stores we work with score between 25 and 55 on mobile before optimisation. After addressing app scripts and image delivery, scores of 60 to 80 are typical. Stores on minimal themes with few apps regularly reach 80 or above.
- Does Shopify's built-in CDN help UK stores?
- Shopify's CDN delivers assets from edge nodes close to visitors, which helps with static asset delivery. However, the CDN does not address render-blocking app scripts, large image files, or theme JavaScript — these require optimisation regardless of CDN configuration.
Ready to speed up your Shopify store?
Start with a free speed check. See your current score, Core Web Vitals, and the specific fixes that will make the biggest difference.