Measure before you optimise anything

It's easy to spend an afternoon making changes that feel productive but don't move the number that matters. Start with a real measurement — Google PageSpeed Insights or a similar Core Web Vitals tool — and note the specific numbers for Largest Contentful Paint, Cumulative Layout Shift, and Interaction to Next Paint before changing anything. Otherwise you're optimising by feel, not by evidence.

Images are usually the biggest single win

Unoptimised images are the most common cause of slow-loading pages, and the fix is almost always straightforward. Resize images to the actual dimensions they're displayed at rather than uploading a full-resolution photo and letting CSS shrink it visually — the browser still downloads the full file either way. Modern formats like WebP produce meaningfully smaller files than JPEG or PNG at equivalent visual quality, and most image optimisation plugins can convert automatically on upload.

Caching does more than any plugin bundle

Without caching, every visitor triggers a fresh database query and page build from scratch. A caching plugin generates a static version of each page once and serves that instead, which is dramatically faster and reduces server load at the same time. This single change often has more impact than a dozen smaller tweaks combined.

Reduce what loads before the page is usable

Every extra plugin, font, and script adds a small delay, and those delays compound. Audit installed plugins periodically and remove ones that duplicate functionality or aren't in active use — a common pattern on older WordPress sites is three plugins doing overlapping jobs because they were each added for a specific feature and never cleaned up afterward.

Loading web fonts efficiently matters too: limit the number of font weights loaded, and use font-display: swap so text remains visible while a custom font loads rather than staying invisible.

Server location and infrastructure set the floor

No amount of front-end optimisation fully compensates for a server that's slow to respond in the first place, or one located far from your actual audience. NVMe storage, rather than older spinning disks, meaningfully reduces the time it takes a server to read and serve files, which is why it's worth checking what storage type is actually included in a hosting plan rather than assuming all storage performs the same.

Everything else on this list matters, but it's built on top of that server-level foundation — worth getting right before spending time on the finer details above it.