Improving a website’s performance is mostly ordinary clean-up — lighter images, less code, smarter caching — and an AI can do much of it for you. When a page is slow, people don’t wait; they leave, often before it has finished loading.
When you build with AI or “vibe coding”, the goal early on is simply to get something working — and that’s the right place to start. But the quick route tends to leave a few things behind: unused code, heavy images, scripts that hold the page back from showing. None of it looks dramatic on its own, and together it’s usually why a page feels sluggish. A slow page quietly costs you — higher bounce rates, less engagement, and lower search rankings, since search engines lean towards faster sites.
The advantage today isn’t just building fast — it’s knowing how to make what you build faster.
So, the same way I’d added security layers, I went back over performance — before later turning to SEO. Here are the steps that helped most, in plain English — plus a bonus for sites that have quietly grown too complex.
Code clean-up & simplification
Remove unused JavaScript, repeated CSS and duplicate libraries. A leaner codebase has less to download and less to run, so the page becomes lighter and quicker to respond.
Production-ready assets
Development code is written to be easy for people to read; production code should be easy for browsers to load. Minifying and bundling strips out the slack and packs files efficiently, which cuts their size and speeds up loading.
Image optimisation
Images are usually the heaviest thing on a page. Modern formats (like WebP), sensible compression, and lazy loading — only fetching an image when it’s about to be seen — make a real difference, especially on phones.
Smart script loading
Some scripts block the page from appearing until they’ve finished. Moving the non-essential ones out of that critical path (loading them ‘deferred’ or ‘async’) lets the content show first, and the extras catch up after.
Fewer network requests
Every separate file is another round trip to the server. Combining files where it makes sense, and removing duplicate imports, means fewer trips — and a page that comes together sooner.
Caching & reuse
The first visit has to download everything; later visits shouldn’t. Good caching lets returning visitors reuse what hasn’t changed, so pages load almost instantly the second time around.
Layout stability
Few things feel worse than a button shifting just as you go to tap it. Giving images and elements their proper dimensions up front keeps the layout from jumping as things load — steadier to use, and something search engines now measure.
BonusOne more layer
Simplifying over-engineered architecture
Sometimes the real drag isn’t any single file — it’s how much machinery the site is carrying. AI-built projects can quietly pile up frameworks and layers a smaller site doesn’t need. Replacing that with something simpler tends to make the site both faster and easier to maintain. It’s the biggest change to make, so I’d leave it until last — and only reach for it when the simpler fixes aren’t enough.
None of this turned me into a performance engineer, and it didn’t need to. Most of it was unglamorous clean-up — much of which an AI can do — and the honest test is one you can run yourself: open the site on your phone, on an ordinary connection, and see how it feels. Build it, secure it, help it be found — then make sure it’s fast.
No coding required. Paste this into your AI tool (with access to your code) to work through the same fixes: