My website got slow after AI changes. How do I find out why?
Updated 2026-10-17
Short answer: the usual cause is something the AI added that's much heavier than it looks: a full-size image or logo, a large script, or a library loaded on every page. The page looks the same, so nothing seems wrong, but every visitor downloads the extra weight, and phones feel it most.
It happened to us. An AI coding tool added a logo to this site that was far larger than it needed to be. The site looked fine, the AI said nothing, and the site stayed slow for six months. We only found out when a Preventionlabs report listed the largest files on the page.
How to check it yourself
- Open the slow page, then developer tools, then the Network tab, and reload.
- Sort by size and look at the largest files, especially images.
- Compare that list with what the AI changed: new images, new scripts, new libraries.
- Resize and compress large images, and set their width and height, then check the page again.
What Preventionlabs shows
Every report breaks down what makes your homepage slow: total size, the largest images and scripts, scripts that block the page, caching lifetimes and files from other services, and how long the page takes to download at Lighthouse's slow-mobile speed against Google's 2.5-second mark.
Price
First report free, no card needed. Then A$50 a month, up to 10 domains.