Technical Information
| HTTP Status Code | 200 |
| HTTP Version | HTTP/1.1 |
| HTTPS | ✔ Available |
| IP Address | 188.114.96.2 |
| Server Software | cloudflare |
| CDN | Cloudflare |
| Compression | gzip |
|
ℹ 🔵 Missing HSTS | HTTP Strict Transport Security is not configured. Recommended for HTTPS sites. |
|
ℹ 🔵 Missing Content Security Policy | CSP is not configured. It helps prevent XSS attacks and content injection. |
|
ℹ 🔵 Missing X-Frame-Options | The site can be embedded in iframes by third parties (clickjacking risk). |
HTTP Status Code 200
HTTP Version HTTP/1.1
HTTPS ✔ Available
IP Address 188.114.96.2
Server Software cloudflare
CDN Cloudflare
Compression gzip
ℹ 🔵 Missing HSTS HTTP Strict Transport Security is not configured. Recommended for HTTPS sites.
ℹ 🔵 Missing Content Security Policy CSP is not configured. It helps prevent XSS attacks and content injection.
ℹ 🔵 Missing X-Frame-Options The site can be embedded in iframes by third parties (clickjacking risk).
Performance
| DNS Lookup | 5.2 ms |
| TCP Connect | 9.6 ms |
| TLS Handshake | 17.8 ms |
| Time To First Byte (TTFB) | 382.8 ms |
| Content Download | 68.9 ms |
| Total Response Time | 451.7 ms |
DNS Lookup 5.2 ms
TCP Connect 9.6 ms
TLS Handshake 17.8 ms
Time To First Byte (TTFB) 382.8 ms
Content Download 68.9 ms
Total Response Time 451.7 ms
Security
| HTTPS | ✔ Enabled |
| HSTS | ✘ Not configured |
| CSP | ⚠ Not configured |
| X-Frame-Options | ⚠ Not configured |
| X-Content-Type-Options | ⚠ Not configured |
| HTTP/2 | ⚠ HTTP/1.1 |
HTTPS ✔ Enabled
HSTS ✘ Not configured
CSP ⚠ Not configured
X-Frame-Options ⚠ Not configured
X-Content-Type-Options ⚠ Not configured
HTTP/2 ⚠ HTTP/1.1
SEO Quick Check
| Title | hypertextbook |
| Meta Description | Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. |
| Canonical | https://hypertextbook.com |
| Open Graph Title | hypertextbook |
| Open Graph Description | Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. |
| Open Graph Image | https://hypertextbook.com/hypertextbook/og-image.jpg |
| Twitter Card | summary |
| Twitter Title | hypertextbook |
| Twitter Description | Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. |
| Twitter Image | https://hypertextbook.com/hypertextbook/og-image.jpg |
Title hypertextbook Meta Description Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. Canonical https://hypertextbook.com Open Graph Title hypertextbook Open Graph Description Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. Open Graph Image https://hypertextbook.com/hypertextbook/og-image.jpg Twitter Card summary Twitter Title hypertextbook Twitter Description Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. Twitter Image https://hypertextbook.com/hypertextbook/og-image.jpg Detected Technologies
| Technology | jQuery Google Analytics Google Tag Manager Cloudflare |
Technology jQuery Google Analytics Google Tag Manager Cloudflare
HTTP Headers
| Date
| Fri, 21 Aug 2026 08:29:11 GMT |
| Content-type
| text/html |
| Report-to
| {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=XEHCWI5A%2BqImPEJdyS0WSXyPS5dTOdOp%2FbXvy6DZIl3NYzd%2FhylKN%2FxI8yP3PKvwNRPR9StsCkzSJm1M3okQobucYmW4aDT5Zx6Ctn%2BCLiyX8JD89DMCKt%2BctELWHFMJG6A2ifZQSInuU5B7QuMzuw%3D%3D"}]} |
| Vary
| Accept-Encoding |
| Server
| cloudflare |
| Alt-svc
| h3=":443"; ma=86400 |
| X-turbo-charged-by
| LiteSpeed |
| Cf-cache-status
| DYNAMIC |
| Nel
| {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800} |
| Server-timing
| cfEdge;dur=12,cfOrigin;dur=337 |
| Content-encoding
| gzip |
| Cf-ray
| a2e844c33af19794-CDG |
Meta Tags
| Viewport | width=416 |
| Author | Glenn Elert |
| Apple-mobile-web-app-title | hypertextbook |
| Application-name | hypertextbook |
| Msapplication-config | https://hypertextbook.com/hypertextbook/browserconfig.xml |
| Msapplication-TileColor | #001f3d |
| Theme-color | #ffffff |
| Description | Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more. |
Date Fri, 21 Aug 2026 08:29:11 GMT
Content-type text/html
Report-to {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=XEHCWI5A%2BqImPEJdyS0WSXyPS5dTOdOp%2FbXvy6DZIl3NYzd%2FhylKN%2FxI8yP3PKvwNRPR9StsCkzSJm1M3okQobucYmW4aDT5Zx6Ctn%2BCLiyX8JD89DMCKt%2BctELWHFMJG6A2ifZQSInuU5B7QuMzuw%3D%3D"}]}
Vary Accept-Encoding
Server cloudflare
Alt-svc h3=":443"; ma=86400
X-turbo-charged-by LiteSpeed
Cf-cache-status DYNAMIC
Nel {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
Server-timing cfEdge;dur=12,cfOrigin;dur=337
Content-encoding gzip
Cf-ray a2e844c33af19794-CDG
