What powers 
onlinejazyky.cz?
Last seen Sep 2026 · 34 technologies across 16 categories
Advertising
Microsoft Advertising
since Aug 2025
Analytics
Authentication
Apple Sign-in
since Oct 2024
Facebook Login
since Jul 2021
Cookie compliance
Font scripts
Font Awesome
since Nov 2023
Google Font API
since Nov 2023
JavaScript frameworks
JavaScript graphics
Chart.js
since Jul 2021
JavaScript libraries
Miscellaneous
Programming languages
Rich text editors
Quill
since Jul 2021
Security
Tag managers
Google Tag Manager
since May 2017
UI frameworks
Bootstrap
since May 2017
Web frameworks
Ruby on Rails
since Nov 2023
Webmail
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 Oct 2026.
- robots.txt found
- llms.txt not found
- ai.txt not found
- Oct 2026 *: Allowed (was Restricted)
- Sep 2026 *: Restricted (was Allowed)
- Sep 2026 *: Allowed (was Restricted)
- Aug 2026 *: Restricted (was Allowed)
AI Crawlers
No AI crawlers blocked
Audience
- 55% desktop
- 45% phone
Czechia
Where the site's Chrome visitors come from, largest estimated audience first.
Open Page Rank
4.69 / 10 · ranked #340,242 of all domains
63 referring domains · OpenPageRank
Core Web Vitals
| LCP | 1.2 s |
| INP | 75 ms |
| CLS | 0 |
| TTFB | 700 ms |
Real user p75, Chrome UX Report, Aug 2026.
Page
- Weight: 2.5 MB · 98 requests
- Structured data: OpenGraph
Homepage as crawled by the HTTP Archive, Sep 2026.
Infrastructure
- Hosted on VSHOSTING (217.16.188.4)
- DNS: wedos.com
- Email: Google Workspace
- Email security: SPF (soft fail), DMARC monitor only, DNSSEC signed
- SSL: Let's Encrypt, RSA 2048, expires Nov 2026
- Common Crawl link graph: rank 70,209, 16 hosts
- Verified with: Meta Business
DNS records as swept Oct 2026, certificate as seen Oct 2026. How the web is hosted
Subdomains
| Host | Techs |
|---|---|
| student.onlinejazyky.cz | 21 |
| studovna2.onlinejazyky.cz | 19 |
| m.onlinejazyky.cz | 16 |
| testy.onlinejazyky.cz | 12 |
| anglictina-testy.onlinejazyky.cz | 11 |
| nemcina-testy.onlinejazyky.cz | 11 |
| spanelstina-testy.onlinejazyky.cz | 11 |
| www.onlinejazyky.cz | 11 |
| kk.onlinejazyky.cz | 9 |
| onlajnovka.onlinejazyky.cz | 2 |
Full technology history →
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Recent changes
- dropped jPlayer Apr 2026