0sum.cn

🤖 AI Summary

After conducting a thorough safety and legitimacy analysis, 0sum.cn receives a trust score of 56/100, which places it in the "Caution Advised" 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 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 0sum.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.

🤖 AI Summary

Our technology detection engine scanned 0sum.cn and identified 5 distinct technologies across 5 categories. This analysis is performed by examining HTTP response headers, HTML source code patterns, JavaScript library fingerprints, CSS framework signatures, and DNS records. CSS Framework: Tailwind CSS — provides the styling and responsive layout system for 0sum.cn. Build Tool: Vite — bundles and optimizes the JavaScript and CSS assets for 0sum.cn. CDN: Cloudflare — accelerates content delivery by caching assets at edge locations worldwide for 0sum.cn. Fonts: Google Fonts — delivers web fonts for typography for 0sum.cn. Icon Set: Font Awesome — provides additional functionality for 0sum.cn.

🤖 AI Summary

0sum.cn delivers its homepage in 35914ms (server response time), which is considered slow by industry standards. The total page weight is 83 KB, and we detected 71 resource requests loading assets from 18 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. No compression is currently enabled on 0sum.cn. Enabling Brotli or Gzip compression could reduce page size by 60-80% for text-based assets (HTML, CSS, JavaScript), significantly improving load times and reducing bandwidth costs. This is one of the simplest and most impactful performance optimizations available. Asset minification status: 1 out of 2 CSS files and 0 out of 1 JavaScript files are minified. Minifying the remaining 2 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 0sum.cn produces approximately 0.04g 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 83 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for 0sum.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.

🤖 AI Summary

0sum.cn resolves to the IPv4 address 47.98.210.31, 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: dns27.hichina.com and dns28.hichina.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 0sum.cn is handled by feishu.cn with 3 MX records configured: mx1.feishu.cn, mx2.feishu.cn, and mx3.feishu.cn. 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 0sum.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. Our subdomain enumeration scan discovered 3 active subdomains for 0sum.cn: mail.0sum.cn, smtp.0sum.cn, and www.0sum.cn. Active subdomains can reveal the organization's infrastructure, including development environments, API endpoints, and third-party service integrations.

🤖 AI Summary

The homepage of 0sum.cn contains 191 words of visible text content. This is a relatively short page — adding more descriptive content could improve search engine visibility. The page is structured with 5 H2 headings, 15 H3 headings, 4 H4 headings. The page includes 14 images. 6 images (43%) 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 57% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 27 internal links pointing to other pages on the same domain and 13 external links pointing to third-party websites. There are 1 external JavaScript files, 2 CSS stylesheets, and 0 iframes on the page. Notable missing features: XML Sitemap, robots.txt, and Schema.org structured data. Adding these could improve search engine discoverability and rich result eligibility.

🤖 AI Summary

The title tag for 0sum.cn is good at 27 characters: "零和塾 Zerosum Edu | 理工科留学专业辅导". The length is acceptable, though it may be slightly truncated in some search result displays. No meta description is configured for 0sum.cn. This is a critical SEO oversight — without a meta description, Google will auto-generate a snippet from page content, which may not accurately represent the page or entice users to click. Adding a unique, compelling meta description of 120-155 characters is strongly recommended. The page language is declared as zh-cn. No Open Graph tags are configured. When someone shares a link to 0sum.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.

🤖 AI Summary

Related domain discovery works by finding other websites that share the same IP address, Google Tag Manager container ID, Google Analytics property, or advertising pixel IDs with 0sum.cn. This data becomes available after batch-crawling the domain database — individual domain lookups cannot populate this section. No tracking IDs were detected on this page that could be used for cross-domain matching.