Have you ever been told to “just compress your images” to fix your slow website?
Or maybe you’ve invested in a fancy caching addon, only to see your conversion rate barely budge.
If so, you’re not alone – and you’re not crazy.
The e-commerce world is full of outdated advice about site speed. But in today’s issue, I wanted to pull back the curtain on the real reasons your store might still be underperforming… even after you’ve “optimized everything.”
Let’s get into it.
The Myth of Image Optimization
Here’s what most guides (and some developers) will tell you:
- Compress images
- Minify CSS and JavaScript
- Use lazy loading
- Install a caching plugin
These steps aren’t wrong – they’re just table stakes.
It’s like telling a racecar driver to “check the tire pressure” and thinking that alone will win the Grand Prix.
In reality, most performance issues that actually hurt conversions go far deeper – and are hiding in plain sight.
What’s Actually Slowing You Down
Let’s talk about what really kills performance (and sales):
1. Third-Party Scripts You Forgot About
Pixel tracking. Heatmaps. Review widgets. Social share buttons. Exit-intent popups.
These are sneaky little demons. One by one, they don’t seem like much. But stack them up and they can turn your store into a digital molasses pit.
Each script can add 100–500ms of load time, and even worse, many block rendering. That means your customer is staring at a blank screen while your popup plugin loads.
Solution: Audit your site with tools like WebPageTest or Chrome DevTools → Performance. Eliminate or defer anything non-essential.
2. Oversized JavaScript Frameworks
If your store runs on a bloated frontend framework (looking at you, React SPAs that mimic Shopify), your “fast” server doesn’t matter. You’re shipping megabytes of JavaScript that users don’t need.
And on mobile? That’s a guaranteed bounce.
Solution: Go lightweight. Vanilla JS when possible. Use server-side rendering (SSR) or static site generation (SSG). Stop treating your online store like a Silicon Valley SaaS app.
3. Layout Shifts That Frustrate Users
Ever try to click “Add to Cart” and bam – the button jumps because the font finished loading?
This isn’t just annoying. It creates a subtle trust break. Your shopper gets distracted or doubts your site’s quality. And it does impact conversions.
Solution: Use font-display: swap, reserve space for dynamic content, and audit your CLS (Cumulative Layout Shift) score in Core Web Vitals.
The Real Metric That Matters: Time to Interaction
Google’s PageSpeed score is like a credit score – nice to have, but often gamed.
What you should care about is how quickly users can actually do something on your site – search, browse, add to cart.
Not just when the spinner stops spinning.
Time to Interaction (TTI) and First Input Delay (FID) are better north stars.
If your store is interactive in under 3 seconds, you’re in the top tier. Over 5 seconds? You’re leaking money.
Today’s Action Steps
Here’s how to start diagnosing and fixing what really matters:
- Run your homepage, collection page, and product page through WebPageTest. Focus on Time to First Byte (TTFB), TTI, and Total Blocking Time (TBT).
- Audit third-party scripts. Use Chrome DevTools > Performance > “Network” tab. Sort by file size and impact. Kill what you don’t need.
- Benchmark mobile. Your dev team probably uses MacBook Pros on fiber. Your customers don’t. Use a throttled 3G simulation to see what they see – instructions to emulate this are here.
- Ditch what doesn’t move the needle. Fancy animations? Reviews widget on every page? Think ROI. Every byte should justify its place.
One More Thing
Speed is not just a technical metric. It’s a trust signal.
Nowadays where your customer is bombarded with choices, waiting feels like a red flag.
And while everyone else is obsessing over Lighthouse scores, you’ll be building a site that actually sells.
Until next time – optimize like a pro, not a plugin.