The Generator theme was built specifically for HubSpot CMS users who want clean design, full control, and fast‑loading pages—without needing to touch a line of code. It’s designed from the ground up with performance in mind, so you’re not fighting against your theme every time you add content.
That said, even with a fast theme and a powerful CMS, page speed still depends on how your site is built. This guide explains what’s already handled for you behind the scenes—and what you, as a non‑technical site manager, can do to keep your site fast.
The Generator theme includes performance best practices out of the box. Most of the technical decisions that affect speed are already made for you, so you don’t have to think about them while building your pages.
Generator is designed to avoid unnecessary bloat. It keeps page weight low, limits the number of requests the browser needs to make, and avoids loading anything that isn’t needed.
Instead of relying on large libraries like jQuery, Generator uses modern, lightweight JavaScript. This reduces file size and improves responsiveness, especially on mobile devices.
Stylesheets and scripts are loaded at the bottom of the page, allowing the visible content to appear first. This prevents render‑blocking and helps pages feel faster as they load.
Only the code for modules that are actually used on a page is loaded. If a feature isn’t present on the page, it isn’t slowing anything down.
Images are lazy loaded by default, meaning they only load when a visitor scrolls to them. This significantly improves initial page load time.
HubSpot CMS takes care of many advanced performance optimizations behind the scenes. These features require no setup and work automatically with the Generator theme.
All assets are delivered through HubSpot’s global CDN, ensuring fast load times regardless of where visitors are located. Images are automatically converted to modern formats like WebP when supported.
HubSpot compresses your site’s code using Brotli or GZIP and applies smart browser caching so repeat visitors experience faster load times.
Your CSS and JavaScript files are automatically cleaned and reduced in size to improve performance without affecting functionality.
Blog posts support AMP for faster mobile performance, and some pages are prerendered so they load more quickly during navigation.
HubSpot ensures that module‑level CSS and JS are only loaded once, even if the same module appears multiple times on a page.
With HubSpot and the Generator theme handling the technical foundation, your role is to make smart content and layout decisions. The biggest performance gains come from a few simple areas that are completely under your control.
Images are the most common cause of slow HubSpot websites—and the easiest thing to fix.
Before uploading an image, think about how much space it will take up on the page. Once you know the approximate display size, double that width to support retina screens.
For example, if an image displays at 600px wide, upload it at 1200px wide. This keeps images sharp without wasting bandwidth on oversized files.
Use JPEG for most images, especially photos or large visuals. JPEGs are smaller and load faster.
Use PNG only when you need transparency, such as for logos or icons. PNG files are much larger and should be used sparingly.
Even properly sized images are often too large straight out of a design tool or camera. Always compress images before uploading.
If you use Photoshop, use Save for Web (Shift + Option + Command + S).
If not, use tools like:
TinyPNG
Squoosh
This step alone can reduce file sizes by 50–80% with no visible quality loss.
The Generator theme automatically lazy loads images. This improves page speed by loading images only when they’re about to be seen. In most cases, you should leave this enabled and not override it.
HubSpot forms load additional scripts and make external requests, which can slightly slow down a page.
On conversion‑focused pages—such as landing pages, demo pages, or lead capture pages—this tradeoff is absolutely worth it. Getting the conversion is more important than maximizing page speed.
On non‑conversion pages, such as your homepage or informational pages, consider removing forms if they aren’t tied to a specific goal. Fewer scripts mean faster load times.
A simple rule of thumb:
Conversion page → use a form
Informational page → only use a form if it adds real value
The live chat widget also adds scripts and background activity, which can slightly affect page speed.
On bottom‑of‑funnel pages like pricing or product pages, live chat can be extremely valuable. Answering a last‑minute question may be the difference between a conversion and a bounce, so the performance tradeoff makes sense.
On general browsing pages, live chat is often unnecessary. If speed is a priority, consider disabling it on pages where visitors are just learning or exploring.
Always prioritize conversion intent over raw speed.
You don’t need technical expertise to evaluate your site’s performance.
Go to pagespeed.web.dev and enter the URL of the page you want to test. You’ll receive a score and a list of recommendations.
Focus on:
Mobile performance
Image sizing and compression
Cumulative Layout Shift (CLS)
Large or unused resources
Don’t obsess over getting a perfect score. The goal is a fast, smooth experience for real users—not chasing numbers.