At Unified, I’ve audited dozens of Magento 2 (Adobe Commerce) websites across a variety of industries and brands. I often see the same story, sites still running on the original “Luma” or “Blank” themes introduced when Magento 2 launched in 2015.
Nearly a decade later, these themes are showing their age. Hindsight is of course wonderful but these they were not designed for the cutting-edge speed, mobile-first experience or performance standards that modern eCommerce demands. This results in slow load times, poor mobile scores, and failing Core Web Vitals, all of which directly affect conversion rates and therefore sales.
Why performance matters for your business
A fast, stable, and responsive website reduces friction in the buying journey, meaning customers are far less likely to abandon their cart or look elsewhere. Google now uses Core Web Vitals as a ranking signal, meaning performance can also influence your search visibility. Core Web Vitals are a set of metrics that measure the real-world user experience of your website:
Largest Contentful Paint (LCP) – how quickly your main content becomes visible
Interaction to Next Paint (INP) – how quickly your site responds to user actions like clicks or taps
Cumulative Layout Shift (CLS) – how much your page layout unexpectedly moves while loading
Pass these tests and you will be rewarded with better usability, higher customer satisfaction, and improved organic reach. Fail them, and you risk losing both search traffic and sales. Even a one-second delay in page load can cause a 7% drop in conversions. For a store making £100,000 a month, that is £7,000 in lost sales, every single month.
The most common Magento 2 performance issues we find
While every site is different, the same patterns emerge across most Magento 2 audits we perform:
1. Media optimisation problems
Oversized product and CMS images that are far larger than needed, increasing load times
Missing lazy loading, so off-screen images load immediately instead of only when needed
Use of outdated image formats instead of modern, lightweight options like WebP or AVIF
Impact: Heavier pages take longer to load, hurting your LCP score and frustrating mobile shoppers.
2. Excessive JavaScript load
First-party JS
Luma ships with 100–150 JavaScript files per page by default
Poorly configured bundling can make files larger, not smaller
Non-critical scripts loading too early, blocking page rendering
Third-party JS
Excess marketing tags and tracking scripts loaded via Google Tag Manager
Tools like chat widgets or heatmap trackers running on every page, even if rarely used
Impact: More JavaScript means slower interaction times (INP) and delays before the site becomes usable.
3. Layout shifts (CLS)
Page elements moving as they load due to missing size attributes or injected content from third-party scripts
Styles loading too late, causing visual “jumps”
Impact: A poor visual experience that frustrates shoppers and fails Google’s CLS metric.
4. No or poorly configured CDN
Many Magento sites run without a proper Content Delivery Network, meaning assets load from a single origin server no matter where the customer is
Missing opportunities to optimise image delivery, caching, and script loading
Impact: Slower delivery for customers further from your server and missed gains in LCP and INP scores.
How our audit process works
Our Magento 2 performance audits are designed to identify the biggest wins for your store, both immediately and long-term. We offer:
Non-invasive audits – We can analyse many performance issues without direct access to your code
Full-access audits – Deeper analysis with code and server review for a complete optimisation plan
Clear reporting – Findings explained in plain language, with a priority list based on impact vs. effort
Actionable roadmap – Short-term “quick wins” and a long-term strategy for sustainable performance
Short-term fixes, long-term gains
We understand that discovering your site is under performing can feel daunting. Our approach is to deliver quick improvements to give your store an immediate performance boost while planning a long-term upgrade path. For many merchants, that long-term plan includes migrating from the outdated Luma or Blank theme to a modern frontend solution such as Hyvä - designed from the ground up for speed, user experience, and Core Web Vitals compliance. Whether you stay with Magento and modernise your theme, or explore a full platform migration, Unified will guide you through every step.
Ready to find out what your site is really capable of?
If you suspect your Magento 2 store is running slower than it should or you simply want to future-proof your eCommerce platform, our performance audits can be a great starting point.
Get in touch with Unified today to discover where your site is losing speed, sales, and search visibility, and how we can help.
I lead our development team on wide range of projects - from Magento 2 storefronts using Hyvä, to bespoke Shopify builds and fully custom headless applications. I’m passionate about combining clean code with thoughtful design to create seamless user experiences and scalable digital products.
