What powers 
gjk.cz?
Last seen Sep 2026 · 30 technologies across 18 categories
Analytics
CDN
CMS
Databases
Font scripts
JavaScript libraries
Maps
Miscellaneous
Operating systems
Performance
Photo galleries
Programming languages
Security
Web frameworks
Web server extensions
Web servers
Webmail
WordPress plugins
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 Oct 2026.
- robots.txt found
- llms.txt not found
- ai.txt not found
AI Crawlers
No AI crawlers blocked
Audience
- 65% phone
- 35% desktop
Czechia
Where the site's Chrome visitors come from, largest estimated audience first.
Open Page Rank
4.69 / 10 · ranked #341,002 of all domains
54 referring domains · OpenPageRank
Core Web Vitals
| LCP | 1.6 s |
| INP | 75 ms |
| CLS | 0 |
| TTFB | 800 ms |
Real user p75, Chrome UX Report, Sep 2026.
Page
- Language: Czech
- Weight: 8.7 MB · 64 requests
- WordPress theme: gjk-kepler · all themes
- Structured data: OpenGraph, Twitter Cards
Homepage as crawled by the HTTP Archive, Sep 2026.
Organisation
- Gymnázium Jana Keplera
- Founded: 1932
- Country: Czech Republic
From Wikidata (CC0).
Infrastructure
- Hosted on PE3NY-AS (178.248.252.58)
- Email: no MX record returned
- Email security: DNSSEC signed
- SSL: Let's Encrypt, RSA 2048, expires Jan 2027
- Common Crawl link graph: rank 103,999, 12 hosts
DNS records as swept Oct 2026, certificate as seen Oct 2026. How the web is hosted
Subdomains
| Host | Techs |
|---|---|
| gjk.cz | 21 |
| dochazka.gjk.cz | 9 |
| symposion.gjk.cz | 5 |
Full technology history →
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Recent changes
- detected Priority Hints Jul 2026
- dropped Jetpack Jan 2026
- dropped TablePress Jan 2026
- detected Imagely NextGEN Gallery Dec 2025
- detected Lightbox Dec 2025