Theme Speed Guide · Updated March 2026

Brooklyn Theme Slow? Here's How to Fix It

Brooklyn is a popular legacy Shopify theme designed for apparel stores. Its header slideshow and jQuery base make it slower than modern alternatives. Here's how to optimize it for maximum speed without sacrificing functionality.

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

Brooklyn Theme Overview

Developer

Shopify

Price

Free

Speed Score: Before vs After Optimization

Default (Unoptimized)

65-75

PageSpeed Mobile Score

After Optimization

83-92

PageSpeed Mobile Score

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

Common Speed Issues with Brooklyn

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

Header slideshow with large images loading synchronously

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

jQuery and legacy JavaScript patterns increasing bundle size

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 grid hover effects triggering repaints

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.

No native lazy loading support for images

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 Brooklyn

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

Replace the homepage slideshow with a single optimized hero image

Add loading='lazy' attributes manually to below-fold images in Liquid

Compress hero and collection banner images to WebP under 200KB

Disable hover zoom on product images if not essential for your customers

Limit featured collections on the homepage to reduce initial page weight

Consider upgrading to a modern OS 2.0 theme for better built-in performance

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

You can optimize your Brooklyn 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 Brooklyn Store in 60 Seconds

Thunder automatically identifies which apps are slowing your Brooklyn 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 Brooklyn

Frequently Asked Questions

Why is my Brooklyn theme slow on Shopify?

The Brooklyn theme typically scores 65-75 on PageSpeed Insights out of the box. Common causes of slowness include header slideshow with large images loading synchronously and jquery and legacy javascript patterns increasing bundle size. However, the biggest speed killer for most Brooklyn 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 83-92.

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

For a Brooklyn store, a realistic optimized PageSpeed score is 83-92 on mobile and even higher on desktop. The default unoptimized score is typically 65-75. 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 Brooklyn 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 Brooklyn 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 Brooklyn a fast Shopify theme?

Brooklyn is a free Shopify theme that performs reasonably well out of the box, typically scoring 65-75 on mobile PageSpeed. As a Shopify-built theme, it follows modern performance practices. However, your actual speed depends heavily on your product images, installed apps, and how many sections you use. With optimization, Brooklyn stores can reach 83-92.