How do I speed up a slow website?

Measure first, then fix the biggest cause. For most sites that means compressing oversized images, turning on text compression and caching, deferring unneeded JavaScript and checking that the server answers quickly. Work through one change at a time and retest, so you know what actually helped.

Why it matters

Slow pages frustrate visitors, who may leave before the page appears. Speed is also part of the Core Web Vitals, which Search Console reports. Guessing wastes time: a site slowed by a three megabyte hero image will not be rescued by minifying a small stylesheet.

How to do it

Measure. Run PageSpeed Insights on your main templates (home page, a content page, a product or contact page) on mobile. Note LCP, INP, CLS and the biggest opportunities listed. Write the numbers down.
Fix images first. Images are often the largest files. Resize them to the size they display, compress them and use modern formats such as WebP or AVIF. Add width and height and lazy-load images below the first screen.
Turn on compression. Enable Brotli or gzip for HTML, CSS and JavaScript.
Set caching. Give static files a long Cache-Control lifetime, with versioned file names so updates still reach visitors.
Trim JavaScript. Remove unused plugins and scripts, defer what is not needed for the first view and look hard at third-party tags such as chat widgets and trackers.
Check the server. If Time to First Byte is high, add page caching, look at slow database queries, remove redirect hops or move to stronger hosting.
Consider a CDN. Serving files from locations near visitors helps if your audience is spread out.
Retest. Run the same tests as in step 1 and compare. Later, check field data to see the effect on real visitors.

Common mistakes

Installing a "speed" plugin on top of a heavy theme and expecting a transformation.
Running only desktop tests, when most visitors may be on phones.
Lazy-loading the main image at the top of the page.
Compressing images but leaving the original huge files in use.
Changing five things at once and not knowing which one worked.

Frequently asked questions

What is the fastest fix for most sites?

Image optimisation commonly gives the largest saving. Resizing and compressing a few oversized photos can cut the page weight by a large amount.

How fast should my website be?

Aim for the Core Web Vitals thresholds at the 75th percentile: LCP of 2.5 seconds or less, INP of 200 milliseconds or less and CLS of 0.1 or less.

Will a faster site rank higher?

Speed supports a better experience, but no change can promise rankings. Treat it as a quality improvement for visitors.

Want a prioritised look at your own pages? Try the free website sample.