www.tudelft.nl speed test — 20 Oct 2026

The first byte arrived after 755 ms. Of that, 632 ms was the server thinking and 123 ms was connection setup. A first byte under 400 ms is what a visitor feels as instant.

Fix: Cut server think time: page cache, query indexes, fewer synchronous calls to third parties inside the request. Connection setup is distance, so a nearer region or a CDN edge helps instead.

9 image(s) over 200 KB and 0 large image(s) still served as JPEG or PNG.

Fix: Serve WebP or AVIF with a JPEG fallback, size images to the space they occupy, and lazy-load anything below the fold. Images are usually more than half of a slow page.

The page transfers 16.89 MB across 26 request(s), with the document itself at 32.4 KB.

Fix: Work through the heaviest assets first: images, then fonts, then third-party scripts.

1 asset(s) answer without a Cache-Control max-age, so browsers revalidate them on every visit.

Fix: Version filenames on change and serve them with a long max-age plus immutable. That is what makes a returning visitor fast.

2 third-party host(s) serve 16.86 MB of this page. Each one is another DNS lookup, TLS handshake and point of failure you do not control.

Fix: Self-host the libraries you can, drop the tags you cannot justify, and preconnect the ones you keep.