Technical Information
| HTTP Status Code | 200 |
| HTTP Version | HTTP/1.1 |
| HTTPS | ✔ Available |
| IP Address | 120.55.40.41 |
| Server Software | Microsoft-IIS/10.0 |
| 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. |
|
🕐 🟡 Slow Response (1036 ms) | Response time exceeds 1 second. Consider optimizing the server or using caching. |
|
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 120.55.40.41
Server Software Microsoft-IIS/10.0
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.
🕐 🟡 Slow Response (1036 ms) Response time exceeds 1 second. Consider optimizing the server or using caching.
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://w3school.com.cn:443 | 301 | HTTP/2 301 |
| 2 | https://www.w3school.com.cn/ | 200 | HTTP/2 200 |
#1 URL https://w3school.com.cn:443
HTTP Status Code 301
Status HTTP/2 301
#2 URL https://www.w3school.com.cn/
HTTP Status Code 200
Status HTTP/2 200
Performance
| DNS Lookup | 252.9 ms |
| TCP Connect | 442 ms |
| TLS Handshake | 396.5 ms |
| Time To First Byte (TTFB) | 1035.6 ms |
| Content Download | 0.2 ms |
| Total Response Time | 1035.8 ms |
DNS Lookup 252.9 ms
TCP Connect 442 ms
TLS Handshake 396.5 ms
Time To First Byte (TTFB) 1035.6 ms
Content Download 0.2 ms
Total Response Time 1035.8 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 | W3School 在线教程 |
| Meta Description | 提供结构清晰、通俗易懂的 Web 开发教程，内含海量实战示例，涵盖 HTML、CSS、JavaScript、SQL、Python、PHP、Bootstrap、Java、XML 等多种技术。 |
| Robots Meta | all |
| Open Graph Description | W3School 提供涵盖所有主流 Web 开发语言的免费在线教程、参考手册和练习题。内容包含 HTML、CSS、JavaScript、Python、SQL、Java 等众多热门技术领域。 |
| Open Graph Image | https://www.w3school.com.cn/i/logo/og-1200x630.png |
Title W3School 在线教程 Meta Description 提供结构清晰、通俗易懂的 Web 开发教程，内含海量实战示例，涵盖 HTML、CSS、JavaScript、SQL、Python、PHP、Bootstrap、Java、XML 等多种技术。 Robots Meta all Open Graph Description W3School 提供涵盖所有主流 Web 开发语言的免费在线教程、参考手册和练习题。内容包含 HTML、CSS、JavaScript、Python、SQL、Java 等众多热门技术领域。 Open Graph Image https://www.w3school.com.cn/i/logo/og-1200x630.png Detected Technologies
| Technology | Bootstrap Google Analytics Google Tag Manager Cloudflare PHP Node.js |
Technology Bootstrap Google Analytics Google Tag Manager Cloudflare PHP Node.js
HTTP Headers
| Content-type
| text/html |
| Content-encoding
| gzip |
| Last-modified
| Wed, 22 Apr 2026 14:15:22 GMT |
| Accept-ranges
| bytes |
| Etag
| "0f9a67462d2dc1:0" |
| Vary
| Accept-Encoding |
| Server
| Microsoft-IIS/10.0 |
| X-powered-by
| ASP.NET |
| Date
| Wed, 22 Jul 2026 18:09:06 GMT |
| Content-length
| 6866 |
Meta Tags
| Robots | all |
| Author | w3school.com.cn |
| Viewport | width=device-width, initial-scale=1 |
| Title | W3School.com.cn |
| Keywords | HTML、CSS、JavaScript、SQL、Python、Java、PHP、How to、C、C++、C#、Bootstrap、React、MySQL、jQuery、Excel、XML、Django、NumPy、Pandas、SciPy、NodeJS、TypeScript、Angular、AngularJS、PostgreSQL、MongoDB、ASP、AI、R、Go、Kotlin、Sass、VUE、Git、Bash、Rust、图形、算法、编程入门、Web 开发、数据科学、色彩、图标、代码游戏、编程、教程、培训、学习、测验、练习、课程、课时、参考手册、示例、源代码、演示、技巧、网站 |
| Description | 提供结构清晰、通俗易懂的 Web 开发教程，内含海量实战示例，涵盖 HTML、CSS、JavaScript、SQL、Python、PHP、Bootstrap、Java、XML 等多种技术。 |
| Msapplication-TileColor | #BD2D30 |
| Theme-color | #ffffff |
| Format-detection | telephone=no |
Content-type text/html
Content-encoding gzip
Last-modified Wed, 22 Apr 2026 14:15:22 GMT
Accept-ranges bytes
Etag "0f9a67462d2dc1:0"
Vary Accept-Encoding
Server Microsoft-IIS/10.0
X-powered-by ASP.NET
Date Wed, 22 Jul 2026 18:09:06 GMT
Content-length 6866
