How We Built a Faster HubSpot Website That Converts Better

Performance and conversion go together — especially when traffic comes from paid and organic search.

What is HubSpot CMS Performance?

HubSpot CMS Performance is about optimizing websites built on HubSpot for maximum speed and user experience. This means cleaning up heavy images, deferring unnecessary scripts (like chat and forms), and ensuring the site is stable while loading. The goal is to improve Core Web Vitals to achieve better SEO and a higher conversion rate.

The Problem: Why Do HubSpot Sites Get Slow?

Beautiful websites become slow when design comes at the expense of performance. Large images, third-party scripts, forms, and chat modules all fight for your browser's attention. When you buy a standard HubSpot theme, you often get everything at once — unnecessary code, layout shifts (CLS), and a site that feels sluggish.

→ Read why most HubSpot websites get slow and how to optimize your HubSpot website.

What to take away

**A fast HubSpot website is a marketing asset — not just a technical side project for developers.**

HubSpot CMS Performance covers speed, stability, and interactivity — measured via Core Web Vitals.
Oversized images without `srcset`/`sizes` and dimensions are among the top causes of slow LCP and CLS.
Chat, forms, and tracking should defer until the user needs them — not load in the first second.
You don't need boring design: animate `transform` and `opacity`, not `transition: all`.
Better performance means lower friction, stronger SEO, and higher conversion from the same traffic.

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How We Fixed the Images (and Core Web Vitals)

We changed how HubSpot handles images so the right assets load first — fixing slow load times and annoying layout shifts.

The Right Image for the Right Screen

We added responsive patterns (srcset and sizes) across modules and blog templates. Mobile gets small files; desktop gets large ones. → How we optimized images across our HubSpot theme.

Lazy Loading and Dimensions

Below-the-fold images use lazy loading and async decoding. Explicit dimensions reserve space before load — reducing CLS. Hero images use fetchpriority="high".

Third-Party Scripts: Chat and Forms on Hold

HubSpot chat and forms are great for leads but lethal for speed if they load too early. We built third-party-performance.js to delay chat until consent, intent, or idle capacity. Forms load when the user scrolls toward them. → Third-party scripts killing landing page speed.

Fast Animations Without Compromise

We removed broad transition: all rules and replaced them with specific transitions on transform and opacity, with prefers-reduced-motion support. → Performance without boring design.

In this guide

This page is the hub for HubSpot CMS Performance. Go deeper on each topic via the articles below — written for B2B marketers and technical decision-makers who want speed and conversion.

Why HubSpot websites get slow — common pitfalls and quick fixes.
Core Web Vitals for B2B — what LCP, CLS, and INP mean for the bottom line.
Image optimization in HubSpot — srcset, lazy loading, and dimensions.
Third-party scripts — chat, forms, and tracking without killing TBT.
Performance without boring design — fast animations and rich UI.
Website speed as a marketing problem — why IT and marketing must align.

Why Performance Means More Leads

Speed isn't just a technical exercise — it's a marketing problem. A fast site builds trust, reduces friction, strengthens SEO, and improves ad ROI. By reducing main-thread blocking and layout shift, you get more leads from the exact same traffic.

For the platform itself, see HubSpot implementation. For paid and conversion, see performance marketing.

Frequently asked questions

Why is my HubSpot website slow?
HubSpot sites often load large images, heavy templates, and many third-party scripts at once. Defer chat, forms, and tracking until they're needed.

What are Core Web Vitals?
Google's official user-experience metrics: how fast main content loads (LCP), how fast the page responds (INP/TBT), and whether the layout is stable (CLS).

How do I fix layout shift (CLS) on images?
Set width and height in the image markup so the browser reserves space before the file loads.

Ready for a faster website?

Don't let slow scripts and large images steal your leads. We'll look under the hood and show what's actually hurting conversion.

→ Book a website and performance review

You don't have to choose between a beautiful website and a fast one — you need a theme built for both.

— Make More · HubSpot CMS Performance