w3cschool.cn

We performed a comprehensive analysis of w3cschool.cn on 2026-07-02. The website returned an HTTP 200 status code with a server response time of 3155ms. The page is served over HTTP/2 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 246 KB. The website uses a secure HTTPS connection with a valid SSL certificate issued by Asseco Data Systems S.A. (DV type). The connection is encrypted using TLS 1.3 with the TLS_AES_256_GCM_SHA384 cipher suite and sha256WithRSAEncryption signature algorithm. The certificate covers 2 domain(s) (Subject Alternative Names) and expires on 2026-10-29, which is 119 days from now. The security headers analysis reveals a score of 0/100 (poor). No security headers are configured, which is a significant security concern. However, the site is missing Content-Security-Policy, Strict-Transport-Security (HSTS), X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy, which could expose the site and its users to cross-site scripting (XSS), clickjacking, and other web-based attacks. Our technology detection scan identified 5 technologies across 4 categories powering w3cschool.cn. The detected stack includes Angular, React, Vue.js, Bootstrap, and jQuery 1.8.3.. The site uses Angular as its primary framework. The UI is built with React. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, w3cschool.cn receives an overall trust score of 63/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, w3cschool.cn receives a trust score of 63/100, which places it in the "Likely Safe" category. This score is calculated by evaluating multiple factors including SSL certificate validity, domain registration history, email authentication protocols, security header configuration, and blacklist status across major threat intelligence databases. The analysis identified several positive trust signals: a valid HTTPS connection protecting data in transit, a valid SSL certificate issued by Asseco Data Systems S.A. with 119 days until expiration, and SPF (Sender Policy Framework) email authentication preventing email spoofing. Areas of concern include: the absence of a Content-Security-Policy header, which leaves the site more vulnerable to cross-site scripting (XSS) attacks, no X-Frame-Options header, which could allow the site to be embedded in malicious iframes (clickjacking), missing Referrer-Policy, potentially leaking URL information to third parties, the domain's WHOIS information is hidden behind a privacy service, making it harder to verify the owner's identity, and DNSSEC is not enabled, leaving DNS queries vulnerable to spoofing attacks. While these issues don't necessarily indicate malicious intent, they represent areas where the website's security posture could be improved. We checked w3cschool.cn against 8 major blacklist databases including Google Safe Browsing, Phishtank, Urlhaus, Openphish, Dnsfilter, Spamhaus Dbl, Surbl, and Virustotal. The domain passed all 8 checks with a clean status, meaning it has not been flagged for phishing, malware distribution, spam, or other malicious activities by any of the tested threat intelligence providers.

Our technology detection engine scanned w3cschool.cn and identified 5 distinct technologies across 4 categories. This analysis is performed by examining HTTP response headers, HTML source code patterns, JavaScript library fingerprints, CSS framework signatures, and DNS records. Framework: Angular — provides the application framework and routing for w3cschool.cn. UI Library: React and Vue.js — handles the user interface rendering and component management for w3cschool.cn. CSS Framework: Bootstrap — provides the styling and responsive layout system for w3cschool.cn. JavaScript Library: jQuery (version 1.8.3.) — provides utility functions and DOM manipulation for w3cschool.cn.

w3cschool.cn delivers its homepage in 3155ms (server response time), which is considered slow by industry standards. The total page weight is 246 KB, and we detected 804 resource requests loading assets from 23 third-party domains. A high number of third-party domains can significantly impact page load time due to additional DNS lookups and TLS handshakes required for each domain. The website uses Gzip compression for text-based assets, achieving an estimated 60.0% reduction in transfer size. This reduces bandwidth usage and improves page load times, especially for visitors on slower connections. Asset minification status: 0 out of 3 CSS files and 1 out of 6 JavaScript files are minified. Minifying the remaining 8 unminified file(s) could further reduce page weight by 10-30% for those assets. Minification is a best practice that reduces download sizes without affecting functionality. From an environmental perspective, each page view of w3cschool.cn produces approximately 0.12g of CO₂, earning a carbon rating of A. This places the website among the cleanest on the web, demonstrating efficient use of server resources and optimized content delivery. For reference, the average web page produces about 0.5g of CO₂ per page view. The page weight of 246 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for w3cschool.cn. This typically means the site doesn't have enough real-world Chrome user traffic to generate statistically significant field data, or the domain is not included in the CrUX dataset. Core Web Vitals (LCP, INP, CLS) are important Google ranking factors that measure real user experience.

w3cschool.cn resolves to the IPv4 address 120.79.88.157, but does not support IPv6. IPv6 adoption is increasingly important as IPv4 address space becomes exhausted, and some ISPs and regions are transitioning to IPv6-only connectivity. The domain has 1 A record(s) configured. The domain name system is managed by 2 name servers: ns3.dnsv2.com and ns4.dnsv2.com. Having 2 name servers provides good redundancy — if one fails, the others can continue serving DNS queries. The choice of name servers often indicates the DNS hosting provider or CDN service being used. Email for w3cschool.cn is handled by qq.com with 2 MX records configured: mxbiz1.qq.com and mxbiz2.qq.com. Multiple MX records provide failover redundancy — if the primary mail server is unavailable, email will be routed to the next available server. SPF (Sender Policy Framework) is configured, which specifies which mail servers are authorized to send email on behalf of this domain. This helps prevent email spoofing and improves email deliverability. DMARC is not configured, leaving the domain vulnerable to email spoofing and phishing attacks that impersonate this domain. DKIM was not detected. Without DKIM, recipients cannot cryptographically verify that emails claiming to be from this domain are authentic. DNSSEC is not enabled for w3cschool.cn. While not critical for most websites, DNSSEC adds an important security layer by ensuring DNS responses haven't been tampered with during transit. Enabling DNSSEC is recommended for domains handling sensitive data or financial transactions.

The homepage of w3cschool.cn contains 1,253 words of visible text content. This is a substantial amount of content that provides good opportunities for search engine indexing. The page is structured with 5 H2 headings, 44 H3 headings, 104 H4 headings. The page includes 325 images. 26 images (8%) are missing alt text attributes, which is a significant concern for both accessibility and SEO. Screen readers rely on alt text to describe images to visually impaired users, and search engines use alt text to understand image content. Only 92% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 418 internal links pointing to other pages on the same domain and 28 external links pointing to third-party websites. The high number of internal links suggests a well-interconnected site structure, which helps search engines discover and crawl all pages efficiently. There are 6 external JavaScript files, 3 CSS stylesheets, and 0 iframes on the page. The site implements the following web standards and features: robots.txt (controls search engine crawling behavior). Notable missing features: XML Sitemap and Schema.org structured data. Adding these could improve search engine discoverability and rich result eligibility. The website has social media presence across 1 platforms: Github (@features). An active social media presence is a positive trust indicator and helps build brand awareness and customer engagement.

The title tag for w3cschool.cn is good at 27 characters: "w3cschool官网 - 1000多本编程教程免费学". The length is acceptable, though it may be slightly truncated in some search result displays. The meta description is 153 characters (well-optimized): "w3cschool启用中文品牌名--编程狮，是一个专业的W3C前端开发及编程入门学习平台，提供包括HTML,CSS,Javascript,jQuery,C,PHP,Java,Python,Sql,Mysql等编程语言和开源技术的在线教程及使...". Google typically displays up to 155-160 characters of the meta description in search results. A compelling meta description with a clear call-to-action can significantly improve click-through rates from search results. The canonical url is correctly set to https://www.w3cschool.cn, preventing duplicate content issues, the page language is declared as zh, and a favicon is configured. No Open Graph tags are configured. When someone shares a link to w3cschool.cn on social media, the platform will have to guess the title, description, and image — often producing unattractive or inaccurate previews. Adding OG tags is essential for social media marketing. The meta keywords tag contains 16 terms including w3cschool, 编程狮, web前端开发, 菜鸟教程, and 编程入门教程. Note: Google has officially confirmed that it does not use the meta keywords tag as a ranking signal. However, some other search engines (Bing, Yandex) may still reference it.