What powers 21kschool.com?
Last seen Jun 2026 · 91 technologies across 33 categories
Advertising
Microsoft Advertising
since Mar 2022
Taboola
since Jan 2022
Analytics
Contentsquare
since Jul 2025
Google Analytics
since Sep 2020
Hotjar
since Mar 2022
Linkedin Insight Tag
since Jan 2022
Microsoft Clarity
since Mar 2022
Authentication
Caching
Redis Object Cache
since Nov 2025
CDN
cdnjs
since Jan 2022
Cloudflare
since Jun 2022
Imgix
since May 2023
jsDelivr
since Nov 2023
Unpkg
since May 2023
CMS
CRM
Zoho
since Aug 2022
Customer data platform
Segment
since Oct 2022
Databases
Editors
Amazon SES
since Aug 2022
Google Workspace
since Aug 2022
Sendinblue
since Jan 2023
Zoho Mail
since Aug 2022
Font scripts
Hosting
GoDaddy
since Aug 2022
WordPress Multisite
since Aug 2025
JavaScript frameworks
JavaScript graphics
JavaScript libraries
Live chat
WhatsApp Business Chat
since Dec 2023
Maps
Google Maps
since Apr 2025
Marketing automation
MoEngage
since Mar 2022
Miscellaneous
HTTP/3
since May 2023
Open Graph
since Sep 2022
Popper
since Apr 2026
PWA
since Aug 2022
Webpack
since Mar 2021
Operating systems
Ubuntu
since May 2021
Windows Server
since Apr 2026
PaaS
Amazon Web Services
since Aug 2022
Render
since Jun 2023
Programming languages
Rich text editors
Quill
since Apr 2026
RUM
Datadog
since May 2023
Security
ClickCease
since Feb 2023
Cloudflare Bot Management
since Jun 2023
HSTS
since Sep 2022
reCAPTCHA
since Mar 2026
SEO
Tag managers
Google Tag Manager
since Sep 2020
UI frameworks
Headless UI
since May 2023
Radix UI
since Nov 2025
shadcn/ui
since Nov 2025
Tailwind CSS
since Apr 2022
Video players
Web frameworks
Web servers
Caddy
since Apr 2026
Widgets
Audience
- 78% phone
- 20% desktop
- 2% tablet
India
Philippines
Pakistan
Bangladesh
Malaysia
South Africa
Countries where the site has Chrome traffic, strongest markets first.
Open Page Rank
4.84 / 10 · ranked #262,345 of all domains
153 referring domains · OpenPageRank
Core Web Vitals
| LCP | 1.9 s |
| INP | 150 ms |
| CLS | 0.05 |
| TTFB | 1100 ms |
Real user p75, Chrome UX Report, Jun 2026.
Page
- Language: English (United States)
- CDN: Cloudflare
- Weight: 4.6 MB · 130 requests
- Structured data: JSON-LD, OpenGraph, Twitter Cards
Homepage as crawled by the HTTP Archive, Jul 2026.
Subdomains
| Host | Techs |
|---|---|
| american.21kschool.com | 42 |
| referral.21kschool.com | 42 |
| www.21kschool.com | 35 |
| igcse.21kschool.com | 29 |
| floww.21kschool.com | 25 |
| garages.21kschool.com | 25 |
| admissions.21kschool.com | 17 |
| social.21kschool.com | 16 |
| rollover.21kschool.com | 15 |
| insights.21kschool.com | 14 |
| careers.21kschool.com | 11 |
| 21kschool.com | 10 |
| blog.21kschool.com | 9 |
| learner-happiness.21kschool.com | 8 |
| enroll.21kschool.com | 6 |
Full technology history →
Report an incorrect detection
Recent changes
- dropped Priority Hints Jun 2026
- dropped RSS Jun 2026
- dropped a3 Lazy Load May 2026
- dropped jQuery CDN May 2026
- detected Priority Hints Apr 2026
- detected reCAPTCHA Mar 2026
- dropped Google Hosted Libraries Feb 2026
- detected Bootstrap Icons Jan 2026
- detected Redis Nov 2025
- detected Redis Object Cache Nov 2025
- detected RSS Aug 2025
- detected WordPress Multisite Aug 2025