www.seznam.cz speed test — 20 Oct 2026

Measured from the wfix.shop server on 20 October 2026 at 12:29 UTC. Grade C (73/100), with the screenshots, the timings and the fixes that matter.

https://www.seznam.cz/

20 October 2026 at 12:29 UTC · Free test · report pt_926b3b1578f1
Grade
C
73/100
Performance81/100
Structure62/100

8 audit(s) passed, 8 need work

First byte (TTFB)690 msmeasured from this server
Fully loaded2.16 sfirst byte + slowest asset
Requests26document + assets
Page weight1.26 MBcompressed transfer
HTML document210.7 KBdeflate
ProtocolHTTP/3envoy
Third-party1.04 MBother hosts

Where the first byte went

  • DNS lookup 52 ms 8%
  • TCP connect 184 ms 27%
  • Server wait 454 ms 66%

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

First byteslower than 69% of 4,999 pages tested here690 ms against a median of 448 ms
Page weightheavier than 70% of 4,999 pages tested here1.26 MB against a median of 650.3 KB
Fully loadedslower than 63% of 4,999 pages tested here2.16 s against a median of 1.84 s
Requestssends more requests than 100% of 4,999 pages tested here26 against a median of 26

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 690 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 1.26 MB over 26 request(s). Images files are 84% of it, so resize and recompress the largest images before anything else.
  • The HTML itself arrives deflate-compressed.
  • It runs over HTTP/3, so the assets share a connection instead of opening one each.
  • 83% of the weight comes from other hosts (analytics, fonts, embeds), which also means their slow day becomes your slow day.
  • The largest element took 6.22 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 0.001), so nothing jumps under the reader's cursor.
  • The main thread was blocked for 1.03 s, 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.

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.

Largest contentful paint6.22 sgood is under 2.5 s
Cumulative layout shift0.001under 0.1 is stable
Total blocking time1.03 slong tasks during load
First contentful paint4.10 sfirst content on screen
Browser page weight10.99 MB401 request(s), scripts included
Failed requests5blocked or unreachable
Largest contentful paint6.22 s
Poorgood under 2.5 s, poor over 4 s
Cumulative layout shift0.001
Goodgood under 0.1, poor over 0.25
Total blocking time1.03 s
Poorgood under 200 ms, poor over 600 ms

Page weight by type

What the page is made of

Images 25 requests
1.06 MB 84%

Transfer size, compressed as sent. 26 request(s) in total, 1.26 MB across all of them.

Top issues

Server response time (TTFB)

high impact

The first byte arrived after 690 ms. Of that, 454 ms was the server thinking and 236 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.

Image delivery and format

high impact

1 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.

Render-blocking resources

high impact

4 render-blocking resource(s) in the document head (0 script(s), 4 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

medium impact

The page transfers 1.26 MB across 26 request(s), with the document itself at 210.7 KB.

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

Cache static assets

medium impact

20 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.

Waterfall

Slowest requests

IMAGESd32-a.sdn.cz/d_32/c_static_qG_A/kPw320bnC5CIwXsDBnI…
1.47 s
IMAGESwww.seznam.cz/media/img/logo-white_v2.svg
1.28 s
IMAGESwww.seznam.cz/media/img/weather/night01.svg
1.27 s
IMAGESwww.seznam.cz/media/img/weather/day02.svg
1.20 s
IMAGESfimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fw…
1.13 s
IMAGESfimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fc…
1.13 s
IMAGESfimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fw…
1.12 s
IMAGESfimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fh…
1.11 s
IMAGESfimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fw…
1.11 s
IMAGESfimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fn…
1.10 s

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

RequestTypeStatusTimeSize
https://d32-a.sdn.cz/d_32/c_static_qG_A/kPw320bnC5CIwXsDBnIIRGcy/0227/media/img/dogs/cekajici_loop-160x160.webp 3rd partyimages2001.47 s476.2 KB
https://www.seznam.cz/media/img/logo-white_v2.svgimages2001.28 s4.6 KB
https://www.seznam.cz/media/img/weather/night01.svgimages2001.27 s3.2 KB
https://www.seznam.cz/media/img/weather/day02.svgimages2001.20 s2.9 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.sport.cz%2Fclanek%2Ffotbal-ceska-1-liga-sparta-mela-na-baniku-dostat-cervenou-soudi-komise-resila-i-choreho-vulgarni-gesto-5559134 3rd partyimages2001.13 s28.4 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fcnn.iprima.cz%2Fflyers-senzacne-porazili-colorado-avalanche-necasuv-gol-na-obrat-nestacil-524874 3rd partyimages2001.13 s37.4 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.seznamzpravy.cz%2Fclanek%2Fekonomika-finance-osobni-nouze-i-budovani-kariery-dve-prace-ma-stale-vic-lidi-318060 3rd partyimages2001.12 s30.0 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fhradecka.drbna.cz%2Fzpravy%2F903515-sobotka-vyzval-k-odvolani-reditele-krnap-ohrozuje-podle-nej-chod-spravy.html 3rd partyimages2001.11 s30.2 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.seznamzpravy.cz%2Fclanek%2Fzahranicni-online-trziste-vinted-blokuje-prodej-zbozi-ukradeneho-pri-rabovani-ve-francii-318272 3rd partyimages2001.11 s46.1 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fnasetema.cz%2Fzahranici%2Fproc-ma-trump-rad-putina-a-stavi-se-proti-ukrajine%2F28959%2F 3rd partyimages2001.10 s23.5 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fzpravy.tiscali.cz%2Fduchodci-maji-dostat-dva-tisice-navic-kdo-ale-pujde-do-penze-v-lednu-nedostane-nic-787043 3rd partyimages2001.10 s28.8 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.seznamzpravy.cz%2Fclanek%2Fdomaci-zivot-v-cesku-podvodnici-okradaji-lekare-na-karvinsku-posilaji-jim-falesne-faktury-318281 3rd partyimages2001.10 s26.2 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.irozhlas.cz%2Fzpravy-domov%2Fz-odchodu-spolustraniku-ke-kdu-csl-vini-grolicha-jde-proti-snaze-spojit-se-proti_2610201219_nob 3rd partyimages2001.09 s22.6 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fcnn.iprima.cz%2Fuvizly-autobus-v-praze-v-metropoli-se-tvori-kolony-hasici-se-snazi-vuz-vyprostit-524885 3rd partyimages2001.09 s32.6 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.novinky.cz%2Fclanek%2Fzahranicni-v-pristavu-na-sicilii-vylovili-telo-ceske-turistky-40603763 3rd partyimages2001.09 s28.4 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.finance.cz%2Fclanky%2Fkdy-je-odchod-do-duchodu-koncem-roku-znacne-ztratovy-a-kdy-naopak-ziskovy%2F 3rd partyimages2001.09 s25.9 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fcnn.iprima.cz%2Fdrony-zabily-73-lidi-v-africke-oblasti-abyei-na-uzemi-zuri-obcanska-valka-524879 3rd partyimages2001.08 s40.6 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.novinky.cz%2Fclanek%2Fdomaci-prijmy-z-dobrovolne-prostituce-podlehaji-zdaneni-40603744 3rd partyimages2001.08 s36.7 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fct24.ceskatelevize.cz%2Fclanek%2Fregiony%2Fjihomoravsky-kraj%2Fv-brne-se-domluvilo-na-koalici-pet-subjektu-378821 3rd partyimages2001.08 s14.6 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fct24.ceskatelevize.cz%2Fclanek%2Fsvet%2Fnocni-zakaz-vychazeni-zajistil-ve-francii-klid-prohlasil-lecornu-378809 3rd partyimages2001.08 s36.1 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fcnn.iprima.cz%2Fposledni-rozlouceni-s-hercem-jirim-stepnickou-vystoupi-medvecka-i-orozovic-524877 3rd partyimages2001.08 s24.0 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.novinky.cz%2Fclanek%2Fkrimi-na-dalnici-d3-u-ceskych-budejovic-se-srazila-tri-auta-40603802 3rd partyimages2001.08 s23.5 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.extra.cz%2Fzpravy-babis-zuri-po-neuspechu-ano-schillerove-dal-poradny-kartac-d2ac7 3rd partyimages2001.08 s25.1 KB
https://fimg-resp.seznam.cz/thumbnail/v1.0/preview/https%3A%2F%2Fwww.extra.cz%2Fnecekana-rana-pro-fanousky-marcela-zmozka-konec-kariery-a-vazna-nemoc-c368b 3rd partyimages2001.08 s31.6 KB
https://www.seznam.cz/media/img/logo_v2.svgimages2001.07 s4.6 KB
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