What powers arcus9.cz?
Last seen Aug 2026 · 15 technologies across 9 categories
Font scripts
Google Font API
since Jan 2019
JavaScript libraries
Miscellaneous
HTTP/3
since Oct 2023
Open Graph
since Sep 2022
Operating systems
Windows Server
since Jan 2019
Security
HSTS
since Sep 2022
UI frameworks
Pure CSS
since Jun 2026
Web frameworks
Microsoft ASP.NET
since Jan 2019
Web servers
Webmail
Apple iCloud Mail
since Feb 2025
Google Workspace
since Aug 2022
AI Crawlers
Doesn't mention any of the 33 AI crawlers we track in its robots.txt; all are allowed by default. Checked Aug 2026.
- robots.txt found
- llms.txt not found
- ai.txt not found
AI Crawlers
No AI crawlers blocked
Audience
Czechia
Where the site's Chrome visitors come from, largest estimated audience first.
Open Page Rank
2.40 / 10 · ranked #2,687,586 of all domains
15 referring domains · OpenPageRank
Core Web Vitals
| LCP | 0.8 s |
| INP | 75 ms |
| CLS | 0 |
| TTFB | 200 ms |
Real user p75, Chrome UX Report, Aug 2026.
Page
- Language: Czech
- Weight: 0.9 MB · 44 requests
- Structured data: JSON-LD, OpenGraph
Homepage as crawled by the HTTP Archive, Sep 2026.
Subdomains
| Host | Techs |
|---|---|
| arcus9.cz | 11 |
| cestovniruch.arcus9.cz | 10 |
| gymnazium.arcus9.cz | 10 |
| multimedialnitvorba.arcus9.cz | 10 |
| www.arcus9.cz | 8 |
| gate1.arcus9.cz | 7 |
| gate2.arcus9.cz | 5 |
Full technology history →
Report an incorrect detection
Recent changes
- detected Pure CSS Jun 2026
- dropped cdnjs Oct 2025
- dropped Cloudflare Oct 2025
- dropped Font Awesome Oct 2025