Theme Performance Guide · Updated Mar 30, 2026

Empire Theme Slow? 44 → 82+ Speed Fix (2026)

Empire by Pixel Union ($350) is Shopify's go-to theme for high-volume stores with large catalogs — often called 'the Amazon theme' for Shopify. Its powerful faceted search, product comparison, and mega-menu features make it ideal for stores with 500+ SKUs. However, these features come with a significant JavaScript cost. In 2026, Pixel Union has emphasized deeper Shopify OS 2.0 integration and speed optimization, but Empire stores still face challenges with Core Web Vitals — particularly INP and LCP on collection pages where filtering JavaScript competes with product image loading. Stores running 15+ apps (common for Empire's target market of large catalogs) see the most dramatic improvements from script optimization. Here's how to optimize it for maximum speed without sacrificing functionality.

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

Empire Theme Overview

Developer

Pixel Union

Price

$350

Speed Score: Before vs After Optimization

Default (Unoptimized)

44-56

PageSpeed Mobile Score

After Optimization

68-82

PageSpeed Mobile Score

These scores represent typical ranges we see across Empire 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 Empire store with a reasonable number of apps installed.

Common Speed Issues with Empire

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

Amazon-inspired layout with heavy product filtering JavaScript — Empire's faceted search loads 80-150KB of JS for filter logic alone

This is typically the largest contributor to slow Largest Contentful Paint (LCP) scores on Empire 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.

Sidebar filters and faceted search adding significant script overhead, especially on collection pages with 6+ filter types active

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).

Product comparison features loading extra JavaScript (~40KB) on every collection page, even when customers rarely use comparison

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.

Large product grids defaulting to 36-48 items per page — each product card includes hover effects, quick-view triggers, and badge overlays that add DOM complexity

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

Multiple inventory and fulfillment app scripts competing for main thread — Empire stores typically run 15-20 apps for catalog management, making script deferral critical

Step-by-Step: How to Speed Up Empire

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

Reduce products per page to 20-24 — Empire defaults to showing many products per page, and each card renders hover effects and badge overlays that multiply DOM size

Disable the product comparison feature in theme settings if your analytics show low usage — it loads ~40KB of JavaScript on every collection page whether customers use it or not

Simplify sidebar filters to 4-5 essential filter types maximum — each active filter type adds JavaScript event listeners and DOM nodes. Color, Size, Price, and Brand cover 90% of customer needs

Use pagination instead of infinite scroll on collection pages — infinite scroll continuously loads product images and DOM elements, degrading performance as users scroll deeper

Compress product thumbnails aggressively to WebP at 80% quality with 400px max width — Empire shows many thumbnails per page, so savings compound quickly. A 50-product grid with optimized thumbnails can save 2-3MB of image data

Disable category-specific promotional banners on collection pages if click-through data doesn't justify them — each banner adds an eager-loaded image above the fold

Audit and defer third-party scripts — Empire's heavy base JavaScript means third-party apps push total JS execution over the 3.5s threshold. Thunder automatically defers non-critical app scripts without breaking functionality

Use system fonts or limit to 2 font weights — Empire's design language works well with clean sans-serif system fonts, saving 80-120KB of font file downloads

Set fetchpriority='high' on the primary collection page banner image for faster LCP — Empire's collection headers are typically the LCP element on category pages

🔍 SEO bonus: Optimizing your Empire 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 Empire 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 Empire store, third-party app scripts account for 60-80% of total JavaScript execution time.

You can optimize your Empire 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.

Performance Optimization Deep Dives for Empire

These guides cover specific performance optimization techniques that work especially well with the Empire theme:

Image Optimization Guide →

WebP, AVIF, srcset — the complete image performance toolkit

Fix Render-Blocking Resources →

Eliminate JS & CSS that block initial page render

LCP Optimization Guide →

Fix the #1 Core Web Vital most stores fail

Third-Party Script Impact →

How app scripts destroy your speed score

68 Themes Speed Ranked →

Where does Empire rank vs all other themes?

Performance Monitoring →

Track speed regressions before they hurt rankings

⚡ Optimize Your Empire Store in 60 Seconds

Thunder automatically identifies which apps are slowing your Empire 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 Empire

Frequently Asked Questions

Why is my Empire theme slow on Shopify?

The Empire theme typically scores 44-56 on PageSpeed Insights out of the box. Common causes of slowness include amazon-inspired layout with heavy product filtering javascript — empire's faceted search loads 80-150kb of js for filter logic alone and sidebar filters and faceted search adding significant script overhead, especially on collection pages with 6+ filter types active. However, the biggest speed killer for most Empire 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 68-82.

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

For a Empire store, a realistic optimized PageSpeed score is 68-82 on mobile and even higher on desktop. The default unoptimized score is typically 44-56. 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 Empire 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 Empire 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.

What are the best practices for Empire theme performance optimization in 2026?

The most impactful Empire performance best practices for 2026 are: (1) Defer third-party app scripts — they cause 60-80% of speed issues on Empire stores. (2) Use WebP/AVIF images under 200KB with proper srcset sizing. (3) Set fetchpriority="high" on your LCP hero image. (4) Limit homepage sections to 8-10 maximum. (5) Use system fonts or limit custom font weights to 2. (6) Remove unused apps — even one uninstalled app can leave behind theme.liquid snippets. (7) Pass all three Core Web Vitals (LCP under 2.5s, CLS under 0.1, INP under 200ms). Thunder Page Speed Optimizer automates steps 1-3 with one-click installation.

How does Empire compare to other Shopify themes for speed in 2026?

According to Shopify's official Core Web Vitals data (March 2026), Empire is a premium theme that falls in the mid-tier for real-world performance. The fastest themes are Baseline (96.6% CWV pass rate) and Publisher (91.3% for free themes). Your actual speed depends more on installed apps and image optimization than the theme itself — a well-optimized Empire store with Thunder will outperform an unoptimized store on a top-ranked theme. See our full Shopify theme speed comparison for the complete 68-theme ranking.

Is Empire a fast Shopify theme?

Empire is a premium theme by Pixel Union priced at $350. Premium themes tend to be slower than free themes because they include more features, animations, and styling options. Empire typically scores 44-56 on mobile PageSpeed out of the box, but with proper optimization, you can improve that to 68-82.