What powers kosaku.jp?
Last seen Sep 2026 · 10 technologies across 6 categories
Font scripts
Font Awesome
since Sep 2026
JavaScript libraries
decimal.js
since Sep 2026
Security
HSTS
since Sep 2026
UI frameworks
Web servers
Nginx
since Sep 2026
Webmail
Microsoft 365
since Sep 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 Oct 2026.
- robots.txt found
- llms.txt not found
- ai.txt not found
AI Crawlers
No AI crawlers blocked
Audience
Japan
Where the site's Chrome visitors come from, largest estimated audience first.
Open Page Rank
0.45 / 10 · ranked #30,101,763 of all domains
0 referring domains · OpenPageRank
Core Web Vitals
| LCP | 2 s |
| INP | 75 ms |
| CLS | 0 |
| TTFB | 1500 ms |
Real user p75, Chrome UX Report, Sep 2026.
Page
- Language: Japanese
- Weight: 0.7 MB · 40 requests
Homepage as crawled by the HTTP Archive, Oct 2026.
Infrastructure
- Hosted on AICS Otsuka Corp. (157.205.36.76)
- DNS: otsuka-office365.jp
- Email: Microsoft 365
- Email security: SPF (soft fail), DMARC monitor only
- SSL: Let's Encrypt, ECDSA P256, expires Nov 2026
DNS records as swept Oct 2026, certificate as seen Oct 2026. How the web is hosted