www.kth.se speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 15:04 UTC. Grade D (68/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 79 ms 9%
- TCP connect 188 ms 21%
- Server wait 613 ms 70%
Measured on the connection that fetched the HTML. Every other request on the page waits for the end of this bar before it can start.
How this page compares
Every report published here is in this comparison, so it is a reference population of pages tested from one server - not a benchmark of the whole web.
What these numbers mean
- The first byte took 881 ms. Everything else waits for that number, so the server is where to start: caching, a slow query, or an overloaded host.
- The page transfers 2.49 MB over 25 request(s). Images files are 78% of it, so resize and recompress the largest images before anything else.
- The HTML itself arrives gzip-compressed.
- It runs over HTTP/3, so the assets share a connection instead of opening one each.
- The largest element painted at 1.54 s, inside the 2.5 s Google calls good.
- The main thread was blocked for 18 ms in total, which is not enough to feel.
Fix first: Server response time (TTFB) - 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.
Read on one shared server, not a visitor's phone: use it to compare pages against each other, not as a promise about every connection. We fix what these tests find.
Screenshot
What the page looks like
Loaded in headless Chromium on this server. Click an image to open it full size.
Browser render
The same URL loaded in a real browser, so these are the readings curl cannot produce. The grade above is still built from the server measurements.
Page weight by type
What the page is made of
Transfer size, compressed as sent. 25 request(s) in total, 2.49 MB across all of them.
Top issues
Server response time (TTFB)
high impactThe first byte arrived after 881 ms. Of that, 613 ms was the server thinking and 267 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.
Compress text responses
high impact1 text response(s) of 10 KB or more are sent uncompressed, and the document itself is not compressed. That is 537.0 KB of compressible text.
Fix: Turn on brotli (preferred) or gzip for text/css, javascript and text/html in the web server. This is the cheapest win available on almost any site.
Image delivery and format
high impact2 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.
Total page weight
high impactThe page transfers 2.49 MB across 25 request(s), with the document itself at 16.7 KB.
Fix: Work through the heaviest assets first: images, then fonts, then third-party scripts.
Avoid extra redirects
medium impact1 redirect hop(s) before the page load started, each one a full round trip before the first byte.
Fix: Link to the canonical URL (and make sure http, the apex domain and www all point at it) so no visitor pays a redirect first.
Waterfall
Slowest requests
Each bar is one request's own response time, scaled to the slowest. Assets were fetched in parallel, so the bars overlap in real time rather than stacking. first party third party
| Request | Type | Status | Time | Size |
|---|---|---|---|---|
| https://www.kth.se/polopoly_fs/1.1501801.1792067580!/image/IMG_6431.webp | images | 200 | 1.78 s | 661.6 KB |
| https://www.kth.se/polopoly_fs/1.1502443.1792482386!/image/patrik%20hilber%2016_9.webp | images | 200 | 1.75 s | 478.1 KB |
| https://www.kth.se/polopoly_fs/1.1502657.1792505119!/image/Ebba%20Busch%20och%20Tharman%20Shanmugaratnam%20%28Christer%20Gummesson%2C%20KTH%29_920px.webp | images | 200 | 1.65 s | 113.2 KB |
| https://www.kth.se/img/logotype-white-6f02f4554cba157ca832fa452bf242a4.svg | images | 200 | 1.64 s | 55.2 KB |
| https://www.kth.se/login?page= | html | 302 | 1.62 s | 0 B |
| https://www.kth.se/polopoly_fs/1.1047015.1731584499!/image/Anders-So%CC%88derholm-01_Z9M3670-copy_fotograf-Mikael-Sjo%CC%88berg_300dpi_5000x3333px_500_300.webp | images | 200 | 1.61 s | 8.8 KB |
| https://www.kth.se/polopoly_fs/1.1431195.1760508771!/image/KTH%20Vidareutbildning%20kurser%20f%C3%B6r%20yrkesverksamma%20kompetensutveckling%20fortbildningwebp.webp | images | 200 | 1.61 s | 17.8 KB |
| https://www.kth.se/polopoly_fs/1.1393349.1742915954!/image/Industriel%20bioteknologi%2003_1252_550.webp | images | 200 | 1.61 s | 50.3 KB |
| https://www.kth.se/polopoly_fs/1.1341764.1744106023!/image/220606_1023_J_OTW_KTH_0507_500_300.webp | images | 200 | 1.61 s | 35.8 KB |
| https://www.kth.se/polopoly_fs/1.1363857.1729060581!/image/KTHK2R5F_7628orginalhimmel_500_300.jpg | images | 200 | 1.60 s | 45.0 KB |
| https://www.kth.se/polopoly_fs/1.1273722.1692876353!/image/apple-touch-icon-KTH-logo-180x180.png | images | 200 | 1.59 s | 16.6 KB |
| https://www.kth.se/polopoly_fs/1.1273705.1692876856!/favicon.ico | images | 200 | 1.59 s | 1.8 KB |
| https://www.kth.se/polopoly_fs/1.1292383.1731584774!/image/full_hor9_750.webp | images | 200 | 1.58 s | 9.2 KB |
| https://www.kth.se/polopoly_fs/1.1325798.1792142385!/image/DDH26_puff_500px.webp | images | 200 | 1.58 s | 31.5 KB |
| https://www.kth.se/polopoly_fs/1.1325777.1792142581!/image/matberedskap_startsida_920px.webp | images | 200 | 1.58 s | 96.2 KB |
| https://www.kth.se/css/kth-f00d07494a5ac2b6cdb95ab74a09bc15.css | css | 200 | 1.57 s | 537.0 KB |
| https://www.kth.se/polopoly_fs/1.1279986.1731584626!/image/medarbetare_Z9M9742_500_300.webp | images | 200 | 1.56 s | 12.3 KB |
| https://www.kth.se/polopoly_fs/1.1497784.1790342646!/image/shutterstock_MASK_609_300.webp | images | 200 | 1.56 s | 41.1 KB |
| https://www.kth.se/polopoly_fs/1.1369002.1773991590!/image/dotoppvar_500_300.webp | images | 200 | 1.56 s | 29.7 KB |
| https://www.kth.se/polopoly_fs/1.1247689.1731584593!/image/alumnevenemang_IMG_0010_500_300.webp | images | 200 | 1.56 s | 30.4 KB |
| https://www.kth.se/polopoly_fs/1.1488054.1784103247!/image/fraga-student-erik-hanna-500x300px.webp | images | 200 | 1.56 s | 19.0 KB |
| https://www.kth.se/polopoly_fs/1.1500160.1791368032!/image/_DSC6570_609_300.webp | images | 200 | 1.55 s | 42.7 KB |
| https://www.kth.se/polopoly_fs/1.1474730.1792141687!/image/Livsmedelsberedskap_puff_500px.webp | images | 200 | 1.55 s | 58.8 KB |
| https://www.kth.se/polopoly_fs/1.1464756.1773991821!/image/_DSC7640_920_518.webp | images | 200 | 1.54 s | 140.1 KB |
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