web4u.cz

Observed 2026-07-12T06:47:35.354Z (21h ago). Every field below was attested with an Ed25519 signature at scan time.

Up right now

Runs onCloudflare

DNSSEC on · IPv6 · tranco_40k

Every line above is a signed observation. Check the math at the bottom of the page.

INFRASTRUCTURE MAPwhat web4u.cz actually stands on - every host below is a signed observation

web4u.cz

A / AAAA

81.91.86.192001:1568::19

Cloudflareserves the site

ns.web4u.czns2.web4u.cz

web4u.czanswers its DNS

mx.web4u.cz

web4u.czreceives its email

HTTPS probe

redirect Redirecting (3xx) 301 → https://www.web4u.cz/

HTTP status301

Servercloudflare

TLS protocolHTTP/2

TLS issuernot observed

Behind Cloudflareyes

Response time940 ms

DNS resolutionNOERROR

Redirect chain

https://www.web4u.cz/

Every field above is part of the same signed observation as the records below. Blank means not observed, never "none".

DNS Records

A 1

81.91.86.19

AAAA 1

2001:1568::19

MX 1

10mx.web4u.cz

TXT 7

MS=0394720CC11BB6E64FFED5064A40D0401C20807E
smv=9d9c9b062c03b840
v=spf1 ip4:81.91.87.150 ip4:81.91.87.80 ip4:81.91.87.60 ip4:81.91.87.250 ip4:81.91.87.34/31 ip4:81.91.87.249 ip4:81.91.87.236 ip6:2001:1568:502:1::/64 ip6:2001:1568:502:2::/64 ip6:2001:1568:502:3::/64 ip6:2001:1568::7060 ip6:2001:1568::7236 ip4:77.78.104.121 ip6:2001:1528:137::a include:_spf.jupiter.salesmanago.pl -all
zoho-verification=zb27107936.zmverify.zoho.eu
v=DMARC1;p=reject;sp=none;pct=100;adkim=s;aspf=r;rua=mailto:dmarc@web4u.cz;ruf=mailto:ruf@web4u.cz
v=DKIM1; (detected)
v=DNSSEC1; (detected)

NS 2

ns.web4u.cz
ns2.web4u.cz

SOA 1

ns.web4u.cz admin.web4u.cz

CAA 1

issue letsencrypt.org

TLS Certificates (0)

None.

Subdomains (16)

The proof

Signed at scan time. Check the math yourself. Every line above is part of one signed observation. Re-hash it and check the Ed25519 signature in your own browser; nothing leaves your machine.

Verify this receipt

Put the receipt on your own site. A live badge showing what DomainDrift observes and signs for web4u.cz. It updates itself. It attests a signed observation - not that the site is safe.

<a href="https://domaindrift.io/t/web4u.cz">
  <img src="https://domaindrift.io/badge/web4u.cz.svg"
       width="300" height="64" alt="DomainDrift signed observations for web4u.cz">
</a>

Ed25519 Receipt

Receipt ID: 076b60e8-19a3-47bb-8646-cb313753f3c0
Output Hash: d4bfced507b913ee654d16587caa8895de60877ae7e2926551f3bdd6508ed3e9
Signature: ed25519:75d96408bb49e85488c953d5335826f6a8bd5156b41bf520e16f3f13ed1d45632add1ea78731407ddedbc66ddf8e625f3cf6a49f0ddf5f752c6d830a99c52003
Public Key: ed25519:d610d74ef18f683e5beb859d241d5e67dff0c122e8928b06bec1c2476f4ba27b
Parent: (genesis)
Plane: fast

Verify this in your browser

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