What powers 
c4.cz?
Last seen May 2026 · 8 technologies across 6 categories
Analytics
Google Analytics
since Aug 2018
Font scripts
Google Font API
since Nov 2022
JavaScript libraries
Miscellaneous
HTTP/3
since May 2026
Programming languages
PHP
since Nov 2022
Web Servers
Apache HTTP Server
since May 2017
Nginx
since May 2026
AI Crawlers
Doesn't name any of the 33 AI crawlers we track in its robots.txt. Catch-all rules (User-agent: *) restrict some paths for every crawler, AI or not. Checked Sep 2026.
- robots.txt found
- llms.txt not found
- ai.txt not found
AI Crawlers
No AI crawlers blocked
Open Page Rank
4.69 / 10 · ranked #328,168 of all domains
45 referring domains · OpenPageRank
Infrastructure
- Hosted on ONE-NETWORK (185.102.21.196, IPv6)
- DNS: webglobe.cz
- Email: skok.cz
- Email security: SPF (hard fail), no DMARC record
- SSL: Let's Encrypt, RSA 2048, wildcard, expires Sep 2026
- Common Crawl link graph: rank 899,468, 17 hosts
- Verified with: Google, Microsoft 365
DNS records as swept Sep 2026, certificate as seen Sep 2026. How the web is hosted
Subdomains
| Host | Techs |
|---|---|
| faq.c4.cz | 6 |
| forum.c4.cz | 5 |
| navody.c4.cz | 3 |
| provoz-webu-pozastaven.c4.cz | 1 |