Why Your BigCommerce Store Is Slow (And How to Fix It)
June 9, 2026
By: Tiffany Hindman
Summary: Why is your BigCommerce store slow? It’s usually because of a buildup of oversized images, unnecessary apps, heavy tracking scripts, and theme bloat that accumulates over time and drags down performance.
Nobody builds a slow store on purpose. It happens gradually — an app here, a tracking pixel there, a banner that "just needs to be a little bigger." Then one day you run a speed test and wonder how things got this bad.
The good news is that most BigCommerce performance problems are fixable without rebuilding from scratch. But you have to know where to look.
Start with your images
This sounds obvious, but it's still the most common culprit. Product images shot on a DSLR, homepage banners exported at print resolution, slider images that haven't been touched since the site launched — these are the low-hanging fruit.
Before anything else, check:
- Are you uploading compressed files, or raw exports straight from a camera or design tool?
- Are your homepage banners sized appropriately for how they actually display, or are you serving a 3MB image in a 600px container?
- Have you switched to WebP? It's not a magic fix, but it typically delivers smaller file sizes than JPEG or PNG when properly optimized, often without noticeable quality loss.
- Are sliders and carousels actually earning their place, or are they just heavy decoration?
One well-optimized hero image loads faster than three uncompressed ones, and most visitors won't notice the difference.
Take a hard look at your installed apps
Every BigCommerce app you've added over the years had a reason at the time. But reasons change — campaigns end, strategies shift, tools get replaced — and the scripts those apps inject into your storefront often stick around long after the app itself stopped being useful.
Pull up your app list and go through it with fresh eyes. For each one, ask:
- Is this actively being used right now?
- Does it need to load on every page, or just certain ones?
- Is there a lighter alternative doing the same job?
The usual suspects are live chat tools, heatmap software, loyalty widgets, and review platforms — not because they're bad, but because they tend to load aggressively. A tool that initializes on every page view, even pages where it's irrelevant, is costing you load time you may not realize you're spending.
Your theme might be working against you
Themes age. What started as a clean Stencil build can become something much messier after years of customizations, hotfixes, and "just add this snippet" requests from different teams or agencies.
A few things worth investigating:
- Duplicate JavaScript libraries — it's not unusual to find two or three slider plugins, or multiple versions of jQuery, coexisting in a theme that's been patched over time
- CSS that references layouts or components that no longer exist on the site
- Custom sections that were built for a promotion or campaign and never removed
- External font files loading across every page when they're only used in one or two places
None of these feel like a big deal individually. Collectively, they're the difference between a site that feels snappy and one that feels like it's thinking.
Homepage and category pages carry the most weight
These pages tend to accumulate more than any other part of the site — more content, more widgets, more images, more scripts. And they're also the pages that get the most traffic, so their performance matters more than anywhere else.
Common problems:
- Hero sliders with autoplay enabled and no lazy loading
- Product grids loading every image above and below the fold simultaneously
- Promotional banners that have stacked up over multiple campaigns
- Widgets added during a site update that were never reviewed after launch
Cutting back here usually has a more noticeable impact than optimizing any other page type.
Tracking and marketing scripts add up fast
Most stores end up with more tracking code than they realize. A Meta pixel installed through an app, another added manually, a Google tag set up by one agency and never removed when the next one came in — before long you have a layer of scripts that fire on every page load whether they're needed or not.
A cleaner approach:
- Route everything through a single tag manager so you have one place to see what's actually running
- Audit your pixels — duplicate tags don't give you better data, they just slow things down
- Check whether A/B testing or personalization tools are blocking page rendering while they initialize
- Remove anything tied to campaigns or platforms you're no longer actively using
This is one of those areas where a one-hour audit can produce real results.
Product pages are where speed directly affects revenue
A slow category page is frustrating. A slow product page is a lost sale. These pages deserve specific attention:
- Video embeds should load on demand, not automatically when the page opens
- Image galleries with zoom features often pull in more JavaScript than you'd expect — worth checking what's actually loading
- Review widgets from third-party platforms can be surprisingly heavy; look at whether the full widget needs to initialize immediately or can load after the core content
- Product tabs (specs, shipping info, FAQs) can often load their content lazily rather than all at once
The goal is getting the product name, images, price, and add-to-cart button in front of the customer as fast as possible. Everything else can wait a moment.
Confirm lazy loading is actually working
Most modern BigCommerce themes include lazy loading, but there's a difference between having it enabled by default and it still working correctly after layers of customization, third-party scripts, and theme edits.
Open your browser's developer tools, go to the Network tab, filter by images, and scroll down a category page. If dozens of images load the moment the page opens regardless of where they sit on the page, lazy loading either isn't enabled or isn't working as intended.
When the problem runs deeper
Frontend cleanup makes a real difference on most stores, but not all performance problems live on the frontend. If you've addressed images, scripts, and theme code and things still feel slow, the bottleneck might be somewhere else entirely.
Stores running ERP integrations, real-time inventory syncs, or custom middleware sometimes hit performance ceilings that no amount of image compression will fix. The same goes for stores that have grown significantly and are now running infrastructure that was designed for a fraction of their current volume.
At that point, you're looking at an architectural conversation — how data moves between systems, where latency is being introduced, and whether the integrations were built to scale or just built to work.
Moving Forward Together
Performance problems in BigCommerce rarely have a single cause. They're usually the result of years of reasonable decisions that, taken together, added more weight than the storefront can carry comfortably. The fix is the same process in reverse: methodical, incremental, and focused on what actually matters to the people trying to buy from you.
To learn more about how Strabo Partners can help, visit Strabo Partners eCommerce Solutions.