Technical Information
| HTTP Status Code | 200 |
| HTTP Version | HTTP/1.1 |
| HTTPS | ✔ Available |
| IP Address | 15.197.225.128 |
| Server Software | GitHub.com |
| CDN | CDN (HIT) |
| Compression | gzip |
|
🔒 🟡 Mixed Content (1 HTTP resources) | The page is served over HTTPS but loads 1 resource(s) over HTTP. This may be blocked in modern browsers. |
|
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 15.197.225.128
Server Software GitHub.com
CDN CDN (HIT)
Compression gzip
🔒 🟡 Mixed Content (1 HTTP resources) The page is served over HTTPS but loads 1 resource(s) over HTTP. This may be blocked in modern browsers.
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://nltk.org:443 | 301 | HTTP/2 301 |
| 2 | http://www.nltk.org | 301 | HTTP/1.1 301 Moved Permanently |
| 3 | https://www.nltk.org/ | 200 | HTTP/2 200 |
#1 URL https://nltk.org:443
HTTP Status Code 301
Status HTTP/2 301
#2 URL http://www.nltk.org
HTTP Status Code 301
Status HTTP/1.1 301 Moved Permanently
#3 URL https://www.nltk.org/
HTTP Status Code 200
Status HTTP/2 200
Performance
| DNS Lookup | 0.6 ms |
| TCP Connect | 1.3 ms |
| TLS Handshake | 6.2 ms |
| Time To First Byte (TTFB) | 142 ms |
| Content Download | 0.1 ms |
| Total Response Time | 142.1 ms |
DNS Lookup 0.6 ms
TCP Connect 1.3 ms
TLS Handshake 6.2 ms
Time To First Byte (TTFB) 142 ms
Content Download 0.1 ms
Total Response Time 142.1 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 | NLTK :: Natural Language Toolkit |
Title NLTK :: Natural Language Toolkit
HTTP Headers
| Server
| GitHub.com |
| Content-type
| text/html; charset=utf-8 |
| X-origin-cache
| HIT |
| Last-modified
| Sun, 23 Nov 2025 05:42:09 GMT |
| Access-control-allow-origin
| * |
| Etag
| W/"69229eb1-2d2f" |
| Expires
| Wed, 22 Jul 2026 19:21:36 GMT |
| Cache-control
| max-age=600 |
| Content-encoding
| gzip |
| X-proxy-cache
| MISS |
| X-github-request-id
| E104:2A3F70:3F997:4057C:6A6115E8 |
| Accept-ranges
| bytes |
| Age
| 0 |
| Date
| Wed, 22 Jul 2026 21:24:38 GMT |
| Via
| 1.1 varnish |
| X-served-by
| cache-par-lfpg1960071-PAR |
| X-cache
| HIT |
| X-cache-hits
| 0 |
| X-timer
| S1784755479.638603,VS0,VE133 |
| Vary
| Accept-Encoding |
| X-fastly-request-id
| 7cd1ba1ad20e2dfe33d4e45a1bfeba25b038d20e |
| Content-length
| 3294 |
Meta Tags
| Viewport | width=device-width, initial-scale=1.0 |
| Theme-color | #2D2D2D |
Server GitHub.com
Content-type text/html; charset=utf-8
X-origin-cache HIT
Last-modified Sun, 23 Nov 2025 05:42:09 GMT
Access-control-allow-origin *
Etag W/"69229eb1-2d2f"
Expires Wed, 22 Jul 2026 19:21:36 GMT
Cache-control max-age=600
Content-encoding gzip
X-proxy-cache MISS
X-github-request-id E104:2A3F70:3F997:4057C:6A6115E8
Accept-ranges bytes
Age 0
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X-served-by cache-par-lfpg1960071-PAR
X-cache HIT
X-cache-hits 0
X-timer S1784755479.638603,VS0,VE133
Vary Accept-Encoding
X-fastly-request-id 7cd1ba1ad20e2dfe33d4e45a1bfeba25b038d20e
Content-length 3294
