What powers os-book.com?
Last seen Sep 2026 · 3 technologies across 3 categories
AI Crawlers
No robots.txt, so all AI crawlers are allowed by default. Checked Sep 2026.
- robots.txt not found
- llms.txt not found
- ai.txt not found
AI Crawlers
No robots.txt, all AI crawlers allowed
Audience
- 55% phone
- 45% desktop
India
United States
Indonesia
Canada
Kenya
Vietnam
Where the site's Chrome visitors come from, largest estimated audience first.
Open Page Rank
3.19 / 10 · ranked #1,275,729 of all domains
39 referring domains · OpenPageRank
Core Web Vitals
| LCP | 1.6 s |
| INP | 250 ms |
| CLS | 0 |
| TTFB | 1500 ms |
Real user p75, Chrome UX Report, Sep 2026.
Page
- Weight: 0.5 MB · 6 requests
Homepage as crawled by the HTTP Archive, Sep 2026.
Infrastructure
- Hosted on YALE-AS (128.36.0.108)
- DNS: Network Solutions
- Email: no MX record returned
- SSL: Let's Encrypt, RSA 2048, expires Dec 2026
- Common Crawl link graph: rank 2,229,529, 2 hosts
- Verified with: Google
DNS records as swept Sep 2026, certificate as seen Sep 2026. How the web is hosted
Subdomains
| Host | Techs |
|---|---|
| os-book.com | 3 |
| www.os-book.com | 3 |