Theme Speed Guide · Updated March 2026

Split Theme Slow? Here's How to Fix It

Split by Fuel Themes features a distinctive split-screen layout. Loading two large images per section doubles the typical image weight per section. Here's how to optimize it for maximum speed without sacrificing functionality.

Running the Split theme? Test your store's speed score for free →

Split Theme Overview

Developer

Fuel Themes

Price

$350

Speed Score: Before vs After Optimization

Default (Unoptimized)

46-58

PageSpeed Mobile Score

After Optimization

70-84

PageSpeed Mobile Score

These scores represent typical ranges we see across Split stores. Your actual score depends on your specific configuration: how many products you display, which apps you've installed, your image sizes, and how many theme sections you use. A store with 5 installed apps will always be slower than one with 2 — regardless of theme choice.

Important context: Shopify's platform itself adds a baseline of JavaScript and CSS that you can't remove. This means no Shopify store will ever score a perfect 100. The scores above represent realistic, achievable targets for a well-optimized Split store with a reasonable number of apps installed.

Common Speed Issues with Split

Every Shopify theme has its own performance characteristics. Here are the speed issues we most commonly see on Split stores, along with why each one matters:

Split-screen layout loading two large images side by side

This is typically the largest contributor to slow Largest Contentful Paint (LCP) scores on Split stores. LCP measures how long it takes for the main visual content to appear — and it's a Core Web Vital that directly affects your Google rankings.

CSS Grid and Flexbox calculations for responsive split panels

Third-party scripts and render-blocking resources prevent the browser from displaying your page until they've downloaded and executed. This increases both First Contentful Paint (FCP) and Time to Interactive (TTI).

Scroll-triggered animations between split sections

Loading too many resources eagerly (before the user scrolls to them) wastes bandwidth and competes with critical above-the-fold content for network and CPU resources.

Multiple high-resolution lifestyle images in each split panel

Excess DOM elements and JavaScript increase the browser's rendering workload, leading to slower interaction responsiveness (measured by Interaction to Next Paint / INP).

Step-by-Step: How to Speed Up Split

Follow these optimization steps in order — they're arranged from highest impact to lowest. Each tip is specific to the Split theme and based on patterns we see across hundreds of Split stores.

Compress both split-panel images — each panel loads a large hero image simultaneously

Disable scroll-triggered animations to reduce JavaScript event listener overhead

Limit split sections on the homepage to 3-4 to reduce total image load

Use WebP at 80% quality for all split-panel images, targeting under 200KB each

Lazy load below-fold split sections to prevent all images loading at once

Reduce image dimensions to 1200px per panel — they don't need full-width resolution

🔍 SEO bonus: Optimizing your Split theme's speed doesn't just improve user experience — it directly impacts your Google search rankings. Stores that pass Core Web Vitals rank higher. Speed optimization is the highest-ROI SEO investment for most Shopify stores.

The #1 Speed Factor Most Split Store Owners Miss

Here's what most speed guides won't tell you: your theme is probably not the main reason your store is slow.

The average Shopify store has 15-25 installed apps, and each one can inject JavaScript and CSS into your storefront. Review apps, email popups, chat widgets, analytics trackers, upsell tools — they all add up. On a typical Split store, third-party app scripts account for 60-80% of total JavaScript execution time.

You can optimize your Split images and settings all day, but if you have a heavy review app loading 200KB of JavaScript and a chat widget initializing a WebSocket connection on every page load, your speed score will still suffer.

This is exactly why we built Thunder. Instead of generic speed tips, Thunder scans every installed app on your store, measures each one's actual speed impact, and shows you exactly what's slowing you down. Then it automatically optimizes how those scripts load — deferring non-essential ones, reducing blocking time, and prioritizing critical functionality.

⚡ Optimize Your Split Store in 60 Seconds

Thunder automatically identifies which apps are slowing your Split store and fixes them — no code changes required. See your speed report instantly.

Install Thunder Free →

Free plan available · No theme code changes · Works with Split

Frequently Asked Questions

Why is my Split theme slow on Shopify?

The Split theme typically scores 46-58 on PageSpeed Insights out of the box. Common causes of slowness include split-screen layout loading two large images side by side and css grid and flexbox calculations for responsive split panels. However, the biggest speed killer for most Split stores is third-party app scripts — review widgets, email popups, and analytics tools that load heavy JavaScript on every page. Optimizing images and deferring non-essential scripts can improve your score to 70-84.

What is a good speed score for a Split Shopify store?

For a Split store, a realistic optimized PageSpeed score is 70-84 on mobile and even higher on desktop. The default unoptimized score is typically 46-58. Don't aim for a perfect 100 — that's nearly impossible with Shopify's platform overhead and any third-party apps. A score above 80 on mobile is considered good, and anything above 90 is excellent.

How do I speed up Split without breaking my store?

Start with safe, high-impact optimizations: compress all images to WebP format, remove unused apps, and enable lazy loading in your Split theme settings. Avoid editing theme code directly unless you're comfortable with Liquid. A speed optimization app like Thunder can automatically defer third-party scripts and optimize loading order without touching your theme files — it's the safest way to improve speed.

Is Split a fast Shopify theme?

Split is a premium theme by Fuel Themes priced at $350. Premium themes tend to be slower than free themes because they include more features, animations, and styling options. Split typically scores 46-58 on mobile PageSpeed out of the box, but with proper optimization, you can improve that to 70-84.