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Does Rep AI Affect Site Speed?

Updated

One of the most common questions merchants ask is whether adding Rep AI to their store will slow it down. The short answer: Rep AI is designed with site speed as a top priority, and its impact on your store's performance is minimal.

This article explains how Rep AI loads on your storefront, what you can expect in terms of performance, and how to verify it yourself.

How Rep AI Loads on Your Store

Rep AI uses a two-stage loading approach specifically designed to protect your site speed:

Stage 1: The Loader (Ultra-Lightweight) When a shopper visits your store, a tiny script called the loader runs first. This script is only ~8 KB — smaller than a single product thumbnail image. It:

  • Detects whether the page is ready

  • Waits for the browser to finish its critical work using requestIdleCallback

  • Only then begins loading the chat widget in the background

Why this matters: The loader never competes with your store's content for bandwidth or processing power. Your product images, navigation, and checkout flow always load first.

Stage 2: The Chat Widget Once the browser is idle, the loader brings in the full chat widget. This happens after your page has already rendered, so your shoppers see your store content before the chat widget appears.

What About Google PageSpeed Insights and Lighthouse?

We know merchants care deeply about their Google PageSpeed Insights (PSI) and Lighthouse scores — they affect SEO rankings and customer experience.

Here's what you should know:

  • Rep AI loads asynchronously — it does not block your page from rendering

  • The loader uses defer and async attributes — the browser treats it as non-critical, loading it after your store's core content

  • Rep AI uses a CDN (Content Delivery Network) — the script is served from the closest geographic location to your shopper, ensuring fast delivery

  • Configuration is cached locally — on repeat visits, Rep AI skips the server call entirely and loads even faster using cached settings (refreshed every 24 hours)

Does Rep AI Affect Core Web Vitals?

Core Web Vitals are the three metrics Google uses to measure real-world user experience:

 
 
 

Metric

 

What It Measures

 

Rep AI's Impact

 

LCP (Largest Contentful Paint)

How fast your main content loads

Minimal — Rep AI loads after your content

INP (Interaction to Next Paint)

How responsive your page feels

Minimal — Rep AI does not block user interactions

CLS (Cumulative Layout Shift)

Whether content jumps around

None — the chat button appears in a fixed position without shifting your page content
 
 
 

Built for Shopify Certified

Rep AI meets Shopify's strict performance requirements for the Built for Shopify badge. This certification requires that apps do not significantly degrade storefront performance, including maintaining LCP under 2.5 seconds at the 75th percentile.

How to Check Rep AI's Impact Yourself

If you'd like to verify Rep AI's impact on your store, here's how:

Option 1: Google PageSpeed Insights

  1. Go to pagespeed.web.dev

  2. Enter your store URL

  3. Run the test

  4. Look at the "Third-party code" section in the diagnostics — Rep AI should have minimal blocking time listed

Option 2: Chrome DevTools

  1. Open your store in Chrome

  2. Press F12 to open DevTools

  3. Go to the Network tab

  4. Reload the page

  5. Filter by JS — you'll see Rep AI's scripts load after your store's core assets

Option 3: Before/After Comparison

  1. Run a Lighthouse test with Rep AI enabled

  2. Temporarily disable Rep AI from your Console (Settings > Widget > Disable)

  3. Run the test again

  4. Compare the scores — the difference should be minimal

Tips for Optimal Performance

  • Keep your Rep AI script tag as provided — it includes defer and async attributes that are essential for non-blocking loading. Don't modify the embed code.

  • Don't duplicate the script tag — having multiple copies of the loader on the same page can cause unnecessary extra loading. Rep AI automatically prevents this, but it's best to have only one script tag.

  • Use the latest embed code — if you installed Rep AI a long time ago, check with our support team to make sure your embed code is up to date with the latest performance optimizations.

What If I Notice a Speed Issue?

If you believe Rep AI is affecting your site speed, here's what to do:

  1. Run a Lighthouse test using the steps above to confirm the impact

  2. Check for other apps — Shopify stores often run 8-12 apps, and the combined effect of all apps is usually the real culprit. Test by disabling apps one at a time.

  3. Contact our support team — share your Lighthouse report and we'll investigate. We take performance seriously and want to help.

Pro Tip: If you're running many apps on your store, chat widgets are often blamed first because they're visible. But the actual performance impact is usually much smaller than it appears. The Lighthouse "Third-party code" diagnostic shows the real numbers — always check there before drawing conclusions.

Our Commitment to Performance

Site speed is not just important to you — it's important to us. A fast-loading widget means:

  • More shoppers engage with your AI — a widget that loads quickly reaches visitors before they bounce

  • Better conversion rates — Google's research shows every 100ms of page delay can reduce conversions

  • Higher merchant satisfaction — we never want to be the reason your store feels slow

We continuously optimize Rep AI's loading performance and monitor our impact on merchant storefronts. Your store's speed is a feature we actively protect.

Questions?

If you have any concerns about Rep AI's impact on your site speed, don't hesitate to reach out to our support team. We're happy to run a performance audit on your specific store and share the results with you.

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