Site speed isn't just a technical problem — it's a business problem. Slow pages lose visitors before they ever read a word, rank lower in search results, and convert at a fraction of the rate of fast ones. The good news is that HubSpot handles more of this than you might think, and the fixes that are left are more manageable than they sound.
This guide walks you through everything you need to know to keep your HubSpot website, landing pages, and blog running fast — without needing a developer for most of it.
Page speed affects nearly every metric you care about as a marketer.
Google uses page speed as a direct ranking factor.
A slow page doesn't just frustrate visitors — it gets buried in search results before they ever find it. Google measures speed through a set of metrics called Core Web Vitals, and pages that fail those benchmarks are at a disadvantage against competitors who pass them.
Most visitors will leave a page that takes more than three seconds to load.
That's not an exaggeration — it's well-documented in Google's own research. Every second of load time increases the likelihood that someone bounces before converting. For landing pages especially, speed is directly tied to campaign performance.
Faster pages convert better, full stop.
A one-second improvement in load time can meaningfully lift form fills, demo requests, and purchases. If you're spending money driving traffic to a slow page, you're leaving results on the table.
One of the advantages of building on HubSpot CMS is that a significant amount of page speed optimization happens behind the scenes without you touching a thing. Before you start worrying about what's slow, it helps to know what's already been taken care of.
HubSpot automatically serves your content through a global Content Delivery Network.
A CDN means your pages load from a server that's physically close to whoever is visiting, rather than from a single location. HubSpot also automatically converts images you upload to WebP format, which is a modern image format that's significantly smaller than JPEG or PNG without any visible loss in quality.
HubSpot automatically strips out all the unnecessary code from your JS and CSS files.
Every space, line break, and comment in a code file adds to its size. Minification removes all of that without changing how anything functions, resulting in smaller files that load faster.
HubSpot tells browsers to store copies of your pages and assets so returning visitors don't have to re-download everything.
This means the second time someone visits your site it loads significantly faster than the first time, which improves experience for repeat visitors and leads.
HubSpot uses modern protocols that allow multiple files to load simultaneously rather than one at a time, and compresses files before sending them to the browser. Both happen automatically with no configuration required.
HubSpot preloads certain page elements before a visitor even clicks, making navigation between pages feel nearly instant.
If you're building your HubSpot site on the Generator theme, a whole additional layer of speed optimization is already built in. Most themes leave these things for a developer to configure. Generator takes care of them out of the box.
Generator runs on Vanilla JS instead of jQuery.
jQuery is a JavaScript library that was ubiquitous for years but adds significant weight to a page. Most modern websites don't need it anymore. Generator skips it entirely, keeping your pages leaner and faster from the start.
Poorly loaded code is one of the most common causes of slow pages.
When JavaScript loads in the wrong place it blocks the rest of the page from rendering until it's finished. Generator loads all CSS and JavaScript just before the closing body tag, which is the correct way to do it and prevents this from happening.
Generator only loads the JavaScript for modules that are actually on the page.
If a module isn't being used on a particular page, its code doesn't load. This keeps every page as lean as possible regardless of how many modules your theme includes overall.
Generator sets all images to lazy load by default.
Lazy loading means images only load when a visitor scrolls down to them, rather than all at once when the page first opens. This dramatically reduces initial load time, especially on image-heavy pages.
Generator includes built-in support for Lottie animations.
Lottie files are lightweight JSON-based animations that are a fraction of the size of animated GIFs. If you want motion on your pages, Lottie is the right way to do it. Most themes don't support them natively — Generator does.
HubSpot and Generator handle a lot, but there are things only you can control. These are the marketer-friendly fixes that don't require a developer and have a direct impact on how fast your pages load.
Oversized images are the number one cause of slow pages.
Before you upload anything to HubSpot, resize it to the dimensions it will actually display at — but double it. Modern retina and high-density screens render images at 2x, so if your image displays in a 400px wide column, you want to upload it at 800px wide. Any larger than that and you're just wasting bandwidth.
Resizing gets you to the right dimensions. Compression gets you to the right file size.
Even a correctly sized image can be bloated if it hasn't been compressed. Run every image through Squoosh before uploading — it's free, browser-based, and lets you see the quality difference side by side before you commit. You can typically cut file size by 70-80% with zero visible difference.
If you're working in Photoshop, use File → Export → Save for Web and set the quality to around 60-70%. It's not as precise as Squoosh but it gets the job done if you're already in Photoshop.
Not all images on your page need to load at the same time.
Lazy loading means images only load when a visitor scrolls down to where they are on the page. Images below the fold — everything a visitor hasn't seen yet — wait until they're needed. This dramatically reduces how much the browser has to load upfront, which speeds up the initial page load significantly.
In HubSpot's drag and drop editor you can enable lazy loading on any image module. If you're on Generator it's already set by default. If you're not, it's worth checking every page to make sure it's turned on.
Animated GIFs are one of the heaviest files you can put on a page.
A single animated GIF can easily be 5-15MB, which is larger than everything else on your page combined. Use MP4 video instead — the file size is a fraction of what a GIF would be, the quality is sharper, and it scales properly on retina screens. For screen recordings and product walkthroughs specifically, Screen Studio is a great tool for creating MP4s that are optimized for web.
For UI animations, icons, and decorative motion use Lottie files instead. They're JSON-based, tiny in file size, and look better than GIFs. If you're on Generator, Lottie support is already built in.
Every font family you load is an additional file the browser has to download before it can render your page.
Limit yourself to one or two font families maximum. Every additional font you add slows things down, and most visitors won't notice the difference anyway. If you're using a font that isn't loading with font-display swap enabled, your page may show invisible text while it waits for the font to load — this is a common issue worth flagging to your developer.
Every third-party widget you add to a page brings its own code with it.
Social media feeds, Calendly widgets, review badges, and chatbots all load external scripts that the browser has to fetch and execute. Each one adds to your load time. Audit what's on your pages and ask whether each embed is earning its place. If something isn't driving results, remove it.
Embed video from YouTube or Vimeo rather than hosting files directly on your HubSpot pages.
YouTube and Vimeo are optimized for delivery, adapt quality based on connection speed, and load efficiently through their embed code. If you need autoplay background video, keep the resolution low and disable it on mobile.
The more modules, sections, and animations you stack on a page the slower it gets.
This is especially common with HubSpot's drag and drop editor where it's easy to keep adding sections. Every element on the page is something the browser has to load and render. Landing pages in particular should be as lean as possible — strip out anything that isn't directly serving the conversion goal.
Both HubSpot forms and the HubSpot live chat widget add external resources that the browser has to load.
Keep forms as simple as possible — fewer fields means less to load. If the form doesn't need to be visible on page load, use a pop-up form that only appears when a visitor clicks a button. For live chat, consider setting it to delayed load so it waits until the page has finished loading before the widget initializes. Neither of these requires a developer to configure.
Broken links slow your page down and make your site look unprofessional.
When a browser hits a broken link it still sends a request and waits for a response before moving on. HubSpot flags broken links automatically in the Recommendations tool, so this is an easy one to stay on top of. Make it a habit to check whenever you delete or unpublish a page.
Knowing what to fix is only useful if you can actually measure where the problems are. These are the tools you should be using to diagnose speed issues and track improvements over time.
This is the first place to check and the one that matters most.
Google PageSpeed Insights analyzes your page and scores it from 0 to 100 for both mobile and desktop. More importantly it tells you exactly what's slowing your page down and prioritizes fixes by impact. Since Google uses these metrics as ranking factors, this is the closest thing to an official report card for your site. Always check both mobile and desktop scores — they are often very different and mobile is the one that matters more.
HubSpot has its own built in performance and SEO recommendations tool that analyzes your pages and surfaces specific issues.
It's not as detailed as PageSpeed Insights but it's tailored to HubSpot specifically and flags things like broken links, missing image dimensions, and other issues that are easy to fix directly in the platform. Check it regularly — it updates as you make changes to your site.
These tools give you a more detailed breakdown of exactly what's loading on your page and in what order.
The waterfall view shows every single file the browser downloads when your page loads, how long each one takes, and whether any are blocking other things from loading. This is more technical than PageSpeed Insights but incredibly useful for identifying specific bottlenecks. If your page is slow and you can't figure out why, the waterfall view will usually tell you.
Core Web Vitals are the three metrics Google uses to measure page experience.
LCP — Largest Contentful Paint. How long it takes for the largest element on the page to load. Usually a hero image or headline. Should be under 2.5 seconds.
CLS — Cumulative Layout Shift. How much the page jumps around while it's loading. You've experienced this when you go to click something and it moves at the last second. Should be as close to zero as possible.
INP — Interaction to Next Paint. How quickly the page responds when a visitor clicks or taps something. Should be under 200 milliseconds.
These three numbers tell you more about real user experience than any overall score. If you're going to focus on anything, focus on these.
Page speed isn't something you set and forget — it's something you maintain.
The good news is that if you're building on HubSpot CMS you're already starting from a strong foundation. HubSpot handles the infrastructure, Generator handles the theme-level optimizations, and the fixes that are left on your plate are manageable without a developer.
The biggest gains almost always come from the same places: images that are too large, fonts that aren't optimized, and third-party scripts that have accumulated over time without anyone questioning whether they're still needed. Start there and you'll see results quickly.
Run PageSpeed Insights on your top five pages today. Fix what it flags. Check back in a week. That's the whole process — it doesn't have to be more complicated than that.