Technical Information
| HTTP Status Code | 200 |
| HTTP Version | HTTP/1.1 |
| HTTPS | ✔ Available |
| IP Address | 18.164.52.68 |
| Server Software | AmazonS3 |
| CDN | CDN (RefreshHit from cloudfront) |
| 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 18.164.52.68
Server Software AmazonS3
CDN CDN (RefreshHit from cloudfront)
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).
Redirect Chain
| # | URL | HTTP Status Code | Status |
| 1 | https://cnx.org:443 | 301 | HTTP/2 301 |
| 2 | https://openstax.org | 200 | HTTP/2 200 |
#1 URL https://cnx.org:443
HTTP Status Code 301
Status HTTP/2 301
#2 URL https://openstax.org
HTTP Status Code 200
Status HTTP/2 200
Performance
| DNS Lookup | 22.3 ms |
| TCP Connect | 23.5 ms |
| TLS Handshake | 7 ms |
| Time To First Byte (TTFB) | 152.3 ms |
| Content Download | 0.2 ms |
| Total Response Time | 152.5 ms |
DNS Lookup 22.3 ms
TCP Connect 23.5 ms
TLS Handshake 7 ms
Time To First Byte (TTFB) 152.3 ms
Content Download 0.2 ms
Total Response Time 152.5 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 | OpenStax |
| Meta Description | OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! |
| Open Graph Title | OpenStax | Free Textbooks Online with No Catch |
| Open Graph Description | OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! |
| Open Graph Image | https://images.openstax.org/apps/image-cdn/v1/assets.open... |
| Twitter Card | summary_large_image |
| Twitter Title | OpenStax | Free Textbooks Online with No Catch |
| Twitter Description | OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! |
| Twitter Image | https://images.openstax.org/apps/image-cdn/v1/assets.open... |
Title OpenStax Meta Description OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! Open Graph Title OpenStax | Free Textbooks Online with No Catch Open Graph Description OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! Open Graph Image https://images.openstax.org/apps/image-cdn/v1/assets.open... Twitter Card summary_large_image Twitter Title OpenStax | Free Textbooks Online with No Catch Twitter Description OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! Twitter Image https://images.openstax.org/apps/image-cdn/v1/assets.open... HTTP Headers
| Content-type
| text/html |
| Last-modified
| Tue, 28 Jul 2026 16:54:37 GMT |
| X-amz-version-id
| .PvQZ8Jte5WIAAFnRUWmQ3i4TKFP7X8d |
| Content-encoding
| gzip |
| Server
| AmazonS3 |
| Date
| Wed, 19 Aug 2026 23:10:29 GMT |
| Cache-control
| public,max-age=60 |
| Etag
| W/"ffe81e53fda21f55216cc9a9352dd2da" |
| Vary
| Accept-Encoding |
| X-cache
| RefreshHit from cloudfront |
| Via
| 1.1 f97045cd1d5b0bf2360d2e427fb0d2ae.cloudfront.net (CloudFront) |
| X-amz-cf-pop
| CDG50-P5 |
| X-amz-cf-id
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Meta Tags
| Viewport | width=device-width,initial-scale=1,maximum-scale=5 |
| Description | OpenStax offers free college textbooks for all types of students, making education accessible & affordable for everyone. Browse our list of available subjects! |
| Mobile-web-app-capable | yes |
| Theme-color | #fff |
| Application-name | @openstax/os-webview |
| Apple-mobile-web-app-capable | yes |
| Apple-mobile-web-app-status-bar-style | black-translucent |
| Apple-mobile-web-app-title | @openstax/os-webview |
| Msapplication-TileColor | #fff |
| Msapplication-TileImage |  |
| Msapplication-config | /dist/assets/browserconfig.xml |
Content-type text/html
Last-modified Tue, 28 Jul 2026 16:54:37 GMT
X-amz-version-id .PvQZ8Jte5WIAAFnRUWmQ3i4TKFP7X8d
Content-encoding gzip
Server AmazonS3
Date Wed, 19 Aug 2026 23:10:29 GMT
Cache-control public,max-age=60
Etag W/"ffe81e53fda21f55216cc9a9352dd2da"
Vary Accept-Encoding
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