Jul 2026 · 4 min read

Why your site is slow — it's almost always the pictures.

Not your host, not your theme, not the code. What page weight actually is, why photographs cause nearly all of it, and the four fixes you can do yourself this afternoon.

A phone in hand at a desk, a laptop open beside it — Photograph: Vitaly Gariev

“The site feels slow.” It's one of the most common things people bring to us, and the answer they expect is a rebuild, a better host, or something clever involving caching. It's usually none of those. Most of the time it's the photographs — which is good news, because the photographs are the one part you can fix yourself, this afternoon, without paying anyone.

What “slow” actually means

Two different numbers both get called speed. The first is how long the server takes to answer at all. That's your hosting, and for most small sites it's already fine. The second is how much the page then sends down the wire before anyone can use it — its weight. That's where the trouble almost always lives. A quick server handing over a heavy page is still a slow website.

The distinction matters because it decides what you should buy. Moving to a faster host when the problem is weight is like hiring a faster van to deliver a piano.

Why it's the pictures

A photo straight off a phone is enormous. Several megabytes, and something like four thousand pixels across. The slot it sits in on your page might be eight hundred pixels wide. If nobody resized it in between, the browser downloads every one of those four thousand pixels and then throws most of them away to make it fit. Your visitor paid for all of them anyway — in data, in battery, in waiting.

Do that four or five times on a homepage and you've built a twenty-megabyte page that looks, on your screen, exactly like a two-megabyte one. That's the cruel part: you will never notice. You're on the office Wi-Fi, and every one of those images is already sitting in your browser's cache from the last time you looked. The person deciding whether to trust you is on a phone, on mobile data, halfway up a stairwell.

A page rarely feels slow because it was badly built. It feels slow because someone sent more than they needed to.

The four things that actually fix it

Roughly in order of how much each one buys you:

01Resize it before you upload it. A picture shown 800 pixels wide should be about 800 pixels wide. This single change usually does more than the other three put together.

02Save photographs as WebP. The same picture, usually a quarter to a third lighter than the equivalent JPEG, and every browser people actually use can read it.

03Let the ones further down wait their turn. Adding loading="lazy" to an image tells the browser not to fetch it until someone scrolls near it. One word, free, and nothing below the fold holds up what someone is actually looking at.

04Give every image a width and a height. It won't save you a single kilobyte, but it stops the text lurching down the page as pictures land — which is most of what “slow” actually feels like.

What light actually looks like

For a sense of scale: we ran our own check-up against this site's homepage in September 2026. It came back at 794kb, counting every one of the nine files the page links to — images and code together, the photograph at the top included. There's nothing clever behind that number. The pictures are sized to the slots they sit in, and they're saved as WebP. That's most of the story.

Worth knowing what that figure is and is not: it counts everything the page references, including the photographs further down that nobody waits for, because rule three above defers them until you scroll near. What a visitor actually waits for on arrival is closer to 580kb. Both numbers are honest; they answer different questions, and any tool that gives you one should tell you which.

And it will not stay 794. It was 537kb when this was first published — the site grew, as sites do. Run it on ours if you like and you will get a third number. That is the argument for measuring rather than trusting anybody's figure, this one included.

You can measure your own in about a minute with the free check-up — it tells you what your page weighs and what's inside it. No email, nothing stored, and you can close the tab and never speak to us. The number is the point, not the conversation afterwards.

One honest caveat: speed isn't everything, and a fast page that says nothing still says nothing. But of all the things you could pay somebody to improve, this is the one you can mostly do yourself — and it's the one your visitors actually feel.