In the world of e-commerce, bigger is usually better. More traffic, more products, more sales. But what about speed? We dove deep into the performance data to uncover the truth. By analyzing over 80,000 Shopify storefronts using data from the HTTP Archive and the Chrome UX Report for June 2025, we uncovered a surprising fact: the smaller, leaner stores are consistently outperforming the giants. This analysis of real-user metadata-from JavaScript size and image weight to theme usage-reveals four distinct types of Shopify stores, why themes are an important performance lever, and what you can learn from the fastest sites on the platform.

Why Core Web Vitals Still Matter

Before diving into what makes some Shopify stores fast and others sluggish, it’s worth revisiting the key performance metrics that shaped our analysis: Core Web Vitals.

These metrics highly correlate to revenue. Many studies have shown that a very strong correlation between sales and page performance & interactivity.

The two metrics we focused on are:

• INP (Interaction to Next Paint) - Measures how quickly a page responds to user input (like clicks and taps). A high INP score means users perceive the site as sluggish.
• LCP (Largest Contentful Paint) - Measures how long it takes for the largest visual element (often a hero image or heading) to appear. A slow LCP affects perceived loading speed.

Both are field metrics, meaning they capture real-user experience. Google uses them to reward fast sites with better rankings. You can check your score here: https://pagespeed.web.dev/

INP and JavaScript Bundle Size

INP is tightly correlated with how much JavaScript the browser has to process. The more JS a site includes-especially third-party scripts-the longer it takes to respond to user actions. Bloated bundles lead to long input delays and poor INP scores.

LCP and Image Weight

LCP, on the other hand, depends heavily on how quickly the page can load its largest visual element. Large, unoptimized images directly hurt LCP by delaying when that primary content becomes visible.

Together, INP and LCP tell us whether a page feels fast. And in a competitive ecommerce environment, that feeling can make or break a conversion.

Act I: The Surprising Speed of the Little Guys

Our story begins with a paradox: many big-name Shopify sites are slowerthan their smaller counterparts. We bucketed sites by popularity rank and looked at what percent failed Google’s Core Web Vitals. The results flipped our expectations:

Figure: Performance vs. Popularity. Even among the top 50k most-visited Shopify sites, a whopping ~25% didn’t meet Core Web Vitals standards (failing either the INP or LCP). Meanwhile, in the broader set of top 1M sites, only about 10% failed. In other words, smaller sites (ranked 500k-1M) were often faster and more efficient than the big brands.

This was a twist - one that had us asking “Why?”. Why would a high-traffic, presumably well-resourced store be _more likely_to have performance issues? The data hinted that as sites grow more popular (and presumably add more features, tracking, A/B testing, or just plain eye-candy), they tend to get heavier and slower, whereas some smaller stores stick to the basics.

Act II: Four Types of Shopify Stores (Which One Are You?)

To dig deeper, we grouped the sites by their characteristics. Think of this like sorting our characters into roles. By running a clustering analysis on page metrics (page weight, script count, and Core Web Vitals), we discovered four distinct archetypesof Shopify sites:

• Lean & Fast: These sites are the sprinters - minimal JS, lightweight images, very few third-party scripts. They load almost instantly and respond to input in a snap.
• Image-Heavy: These stores are loaded with visuals - high-res photos and galleries. They offer rich imagery, but all those bytes of images mean the main content is slower to appear and risking a poor LCP.
• Script-Stuffed: Lots of JavaScript from numerous apps and plugins. These sites have every bell and whistle, but the trade-off is sluggish responsiveness which usually means a higher INP as the browser executes all that code.
• Everything-Heavy: The heavyweight combo. These pages throw in everything - large scripts and large images - resulting in the slowest load times and poorest interactivity.

Let’s see the breakdown of clusters in each popularity rank:

Figure: Shopify Site Archetypes by Popularity. Among elite (top 50k) stores, the “Script-Stuffed” profile dominates (yellow) - over half of big sites fall into this heavy-script category. The nimble “Lean & Fast” sites (gree) are a small minority at the top. But as we move to less popular sites, the roles reverse: the majority of smaller sites are Lean & Fast, and relatively few are script-heavy. (Image-Heavy and Everything-Heavy sites make up the rest, shown in teal and red.)

CVW failure rates across popularity rank buckets:

Key insights

• Failure rates consistently improve as site popularity declines (moving from Top 50k to Top 1M), across all theme types.
• Lean & Fastperforms the best across all rank buckets.
• Image-Heavy themes fall in the middle, worse than Lean & Fast but generally better than Script-Stuffed and Everything-Heavy.
• Everything-Heavythemes have the worst failure rate in the Top 50k (29.6%), but do not consistently perform the worst across all buckets.
• Script-Stuffedthemes are the most failure-prone beyond the Top 50k.

Act III: Themes - Heroes and Villains

Every Shopify store wears a theme, and in our story, the theme can be either a hero or a hidden villain. We wanted to see if certain themes set sites up for success or struggle. The data was emphatic: some themes consistently produced fast sites, while others were commonly associated with slow performance.

Slowest themes

Fastest themes

When it comes to Core Web Vitals performance, not all Shopify themes are created equal. At the bottom of the list, Flexstruggles the most, with nearly 33% of sites failing CWV thresholds, followed closely by Ella (28.2%) and Motion (24%). Other heavy hitters like Empire, Impact, and Expanse also rank poorly, all exceeding an 18% failure rate. These themes often prioritize visual richness and advanced functionality-great for aesthetics, but costly for performance.

On the flip side, some themes excel in speed and user experience. Ride leads the pack with an impressively low 1.6% CWV failure rate, alongside Craft and Minimal, both under 2%. Themes such as Supply, Venture, and Spotlight also deliver strong performance, keeping failure rates below 3%. These lean, performance-first themes prove that streamlined design is key to achieving both beauty and speed.

Why such a difference? Heavy themes often include lots of built-in scripts, sliders, and flashy effects that require extra resources. Lighter themes stick to essentials, making it easier to achieve good speeds. It’s not that a store _can’t_be fast on a feature-rich theme, but it’s fighting an uphill battle. Meanwhile, a store on a lean theme has a head start towards passing Core Web Vitals.

Act IV: Redemption - Improvement is Possible

No story is complete without a redemption arc. The good news in our data saga is that **performance can be turned around.**We saw evidence that developers and merchants who prioritize speed can dramatically improve their outcomes - even if they started off slow.

A striking example is the “Expanse” theme. Earlier versions of Expanse had a poor reputation in our data - around 37% of sites on Expanse v2 failed Core Web Vitals, making it one of the worst performers. But the theme developers went to work on performance, and by Expanse v5 and v6, the failure rate plummeted to around 6%, which is a huge improvement.

Figure: Expanse Theme’s Performance Makeover. This chart shows the percentage of Expanse theme sites failing Core Web Vitals by major version. Version 2 was a laggard (nearly 37% failing), but by version 5, Expanse became much more efficient (only ~6% failing). A major update (coinciding with Shopify’s Online Store 2.0 rollout) turned Expanse from a performance villain into a much more heroic figure.

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Big Wins

Themes like Warehouse and Expanse are prime examples of successful performance evolution. Warehouse improves from a 20.1% CWV failure rate in v2 to just 5.3% in v6, while Expanse makes an even more dramatic leap, dropping from 36.7% in v2 to 5.8% in v6. This suggests a focused effort toward optimization in newer builds. Impact follows a similar arc, with a steep decline from 37.7% in v4 to 9.3% in v6 - an encouraging turnaround.

Themes That Stabilized

Some themes demonstrate a more controlled, gradual improvement. Impulse spans seven versions, with CWV failures ranging from 4.8% to 11.8%, ultimately converging toward more stable territory. Focal trims its failure rate from 14.9% (v8) to 7.6% (v12), showing measured but real progress. Similarly, Prestige starts at 17.2% in v4 and lands at 5.0% in v10, reflecting consistent refinements.

When Updates Go the Wrong Way

Not every upgrade leads to better performance. Turbo illustrates this clearly: its CWV failure rate rises from 11.8% in v4to 23.6% in v7, then slightly improves to 14.0% in v9 - but overall, newer versions tend to perform worse than earlier ones. Flex shows a similar regression, going from 26.9% (v2) to a troubling 42.7% in v5.

Fluctuating and Unpredictable

Then there are themes like Empire, which display no clear trajectory. It begins at a modest 12.4% (v4), spikes to 42.8% in v9, and then drops again to 15.1% in v11. Whether due to changes in feature complexity, asset handling, or regressions in code quality, such swings are red flags for developers prioritizing performance.

Version Choice Matters

Lastly, even smaller shifts can make a big difference. Be Yours improves from 20.3% in v6 to 11.1% in v8, while Broadcast tightens up from 17.3% in v3 to 6.2% in v6. These shifts highlight how choosing the right version of a theme can directly impact CWV success - sometimes more than switching themes entirely.

Conclusion

Versioning isn’t just about new features - it’s about performance health. Shopify merchants aiming to improve Core Web Vitals should treat theme updates as a strategic decision, not a passive one. Sometimes, the best move isn’t switching themes altogether - it’s just upgrading (or downgrading) to the right version.

Likewise, many other themes showed similar turnarounds after updates. And it’s not just themes - individual stores that optimized images, trimmed unnecessary scripts, or removed bloat often moved from failing to passing Core Web Vitals in subsequent data crawls. The overarching theme (pun intended) is that performance is manageable: with effort and focus, a slow site can become fast.

Key Takeaways

• Bigger Isn't Always Faster: Contrary to common belief, smaller, less popular Shopify stores often have better performance and faster load times than larger, more popular ones.
• Themes are Important: The choice of a Shopify theme can have a significant impact on Core Web Vitals. Our data identifies the specific themes that consistently perform the best and worst in real-world conditions.
• Four Store "Types": We've categorized stores into four profiles based on their technical characteristics: Lean & Fast, Image-Heavy, Script-Stuffed, and Everything-Heavy. Understanding your store's profile is the first step to optimization.
• Keep your page Lean & Fast: Only use as much JavaScript (Shopify apps, tracking, A/B testing etc) as truly needed. Optimize your images.
• Improvement is Possible: Poor performance isn't permanent. Themes can and do improve. The "Expanse" theme, for example, went from being one of the slowest to one of the fastest after targeted updates, showing the power of optimization.
• Continuously monitor and tweak to stay fast.