www.centrum.cz speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 14:43 UTC. Grade E (55/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 59 ms 5%
- TCP connect 1 ms 0%
- Server wait 1.03 s 94%
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 1.09 s. Everything else waits for that number, so the server is where to start: caching, a slow query, or an overloaded host.
- The page transfers 3.26 MB over 26 request(s). Other files are 87% of it, so that one type is worth a look on its own.
- The HTML itself arrives br-compressed.
- It runs over HTTP/3, so the assets share a connection instead of opening one each.
- 92% of the weight comes from other hosts (analytics, fonts, embeds), which also means their slow day becomes your slow day.
- The largest element took 2.66 s to paint, past the 2.5 s threshold: usually a hero image that is too big or a render-blocking script in front of it.
- Layout stayed still (CLS 0.014), so nothing jumps under the reader's cursor.
- The main thread was blocked for 227 ms, so taps and scrolling wait while scripts run.
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. 26 request(s) in total, 3.26 MB across all of them.
Top issues
Server response time (TTFB)
high impactThe first byte arrived after 1089 ms. Of that, 1029 ms was the server thinking and 60 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.
Render-blocking resources
high impact3 render-blocking resource(s) in the document head (1 script(s), 2 stylesheet(s)). The page cannot paint until each one arrives.
Fix: Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.
Total page weight
high impactThe page transfers 3.26 MB across 26 request(s), with the document itself at 234.4 KB.
Fix: Work through the heaviest assets first: images, then fonts, then third-party scripts.
Cache static assets
medium impact19 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.
Third-party weight
medium impact4 third-party host(s) serve 2.99 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.
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://ban.maxa.cz/c/1x1.php?pid=33234&sid=42560&bid=48439&tid=11758 3rd party | images | 200 | 1.86 s | 43 B |
| https://hpx-cdn.xsd.cz/articles/92c192c3-7201-5ad8-a8d7-f6794ac14c68/_30m626eNb/146x146.webp 3rd party | images | 200 | 1.64 s | 5.2 KB |
| https://realitymix.centrum.cz/ext-data/hp_short/imgN_8586171.jpg 3rd party | images | 200 | 1.64 s | 68.2 KB |
| https://pocasi-moravio.centrum.cz/public/icons/weather/day/P.svg 3rd party | images | 200 | 1.46 s | 1.9 KB |
| https://hpx-cdn.xsd.cz/horoscope/vodnar.svg 3rd party | images | 200 | 1.42 s | 12.2 KB |
| https://www.centrum.cz/_next/image?url=https%3A%2F%2Fhpx-cdn.xsd.cz%2Fcategories%2Fmenu-benefits-avatar.png&w=640&q=75 | images | 200 | 1.40 s | 13.4 KB |
| https://hpx-cdn.xsd.cz/articles/136ea1e7-d6c0-532c-95da-d53385ecb76b/El07vYe5jD/original.jpg 3rd party | other | 200 | 1.39 s | 46.2 KB |
| https://hpx-cdn.xsd.cz/articles/137b3e5e-4b9d-58fc-b11b-510f3b9d33c6/fnOBbNOUww/146x146.webp 3rd party | images | 200 | 1.38 s | 3.1 KB |
| https://hpx-cdn.xsd.cz/articles/44e16694-77f6-54e8-b504-7412cc1ff2bd/MPt_l3IcOx/original.jpg 3rd party | other | 200 | 1.38 s | 46.2 KB |
| https://hpx-cdn.xsd.cz/articles/928ad575-f076-5f33-97b2-2070ffcfb0dc/qraAbN8dxl/original.webp 3rd party | other | 200 | 1.38 s | 1.96 MB |
| https://hpx-cdn.xsd.cz/articles/137b3e5e-4b9d-58fc-b11b-510f3b9d33c6/fnOBbNOUww/original.jpg 3rd party | other | 200 | 1.37 s | 68.9 KB |
| https://www.centrum.cz/_next/image?url=https%3A%2F%2Fhpx-cdn.xsd.cz%2Fcategories%2Fmenu-benefits-arrow.png&w=1080&q=75 | images | 200 | 1.37 s | 7.3 KB |
| https://hpx-cdn.xsd.cz/articles/136ea1e7-d6c0-532c-95da-d53385ecb76b/El07vYe5jD/w368.webp 3rd party | images | 200 | 1.36 s | 5.8 KB |
| https://hpx-cdn.xsd.cz/articles/928ad575-f076-5f33-97b2-2070ffcfb0dc/qraAbN8dxl/146x146.webp 3rd party | images | 200 | 1.36 s | 5.0 KB |
| https://hpx-cdn.xsd.cz/articles/ccc595f4-188a-5390-893a-83ecfd7bba4e/AXKvY-924g/146x146.webp 3rd party | images | 200 | 1.36 s | 1.4 KB |
| https://www.centrum.cz/_next/image?url=https%3A%2F%2Fhpx-cdn.xsd.cz%2Fcategories%2Fmenu-benefits-avatar.png&w=256&q=75 | images | 200 | 1.35 s | 13.4 KB |
| https://hpx-cdn.xsd.cz/articles/92c192c3-7201-5ad8-a8d7-f6794ac14c68/_30m626eNb/original.jpg 3rd party | other | 200 | 1.35 s | 284.8 KB |
| https://hpx-cdn.xsd.cz/articles/ccc595f4-188a-5390-893a-83ecfd7bba4e/AXKvY-924g/original.jpg 3rd party | other | 200 | 1.34 s | 391.5 KB |
| https://www.centrum.cz/_next/image?url=https%3A%2F%2Fhpx-cdn.xsd.cz%2Fcategories%2Fmenu-benefits-arrow.png&w=640&q=75 | images | 200 | 1.34 s | 8.5 KB |
| https://hpx-cdn.xsd.cz/articles/ce383ba5-9c4f-5d90-8cda-2edb8900cdc6/48nK5a-bFJ/original.jpg 3rd party | other | 200 | 1.33 s | 69.7 KB |
| https://hpx-cdn.xsd.cz/articles/ce383ba5-9c4f-5d90-8cda-2edb8900cdc6/48nK5a-bFJ/w368.webp 3rd party | images | 200 | 1.33 s | 11.5 KB |
| https://hpx-cdn.xsd.cz/centrum.webp 3rd party | images | 200 | 1.32 s | 28.9 KB |
| https://hpx-cdn.xsd.cz/feeds/51/favicon.webp 3rd party | images | 200 | 1.32 s | 612 B |
| https://hpx-cdn.xsd.cz/articles/44e16694-77f6-54e8-b504-7412cc1ff2bd/MPt_l3IcOx/146x146.webp 3rd party | images | 200 | 1.32 s | 2.8 KB |
| https://hpx-cdn.xsd.cz/feeds/147/favicon.webp 3rd party | images | 200 | 1.32 s | 1.5 KB |
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