51zsj.com

We performed a comprehensive analysis of 51zsj.com on 2026-06-28. The website returned an HTTP 200 status code with a server response time of 19713ms. The page is served over HTTP/2 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 75 KB. Warning: The website does not have a valid SSL certificate. Visitors may see security warnings in their browser, and data transmitted to and from this website is not encrypted. The security headers analysis reveals a score of 20/100 (poor). The following security headers are properly configured: Strict-Transport-Security (HSTS). However, the site is missing Content-Security-Policy, 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 2 technologies across 2 categories powering 51zsj.com. The detected stack includes Bootstrap and jQuery 2.1.1.. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, 51zsj.com receives an overall trust score of 60/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, 51zsj.com receives a trust score of 60/100, 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, HSTS (HTTP Strict Transport Security) enforcement preventing protocol downgrade attacks, SPF (Sender Policy Framework) email authentication preventing email spoofing, and a well-established domain registered for over 18.6 years, indicating long-term commitment and legitimacy. 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 51zsj.com 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. The domain is registered through Xiamen ChinaSource Internet Service Co., Ltd based in CN, with a registration date of 2007-12-03 and expiration date of 2030-12-03.

Our technology detection engine scanned 51zsj.com and identified 2 distinct technologies across 2 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: Bootstrap — provides the styling and responsive layout system for 51zsj.com. JavaScript Library: jQuery (version 2.1.1.) — provides utility functions and DOM manipulation for 51zsj.com.

51zsj.com delivers its homepage in 19713ms (server response time), which is considered slow by industry standards. The total page weight is 75 KB, and we detected 518 resource requests loading assets from 11 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 3 out of 13 JavaScript files are minified. Minifying the remaining 13 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 51zsj.com 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 75 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for 51zsj.com. 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.

51zsj.com resolves to the IPv4 address 47.116.210.182, 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: ns1.cnolnic.net and ns2.cnolnic.net. 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 51zsj.com is handled by mxhichina.com with 2 MX records configured: mxn.mxhichina.com and mx.ym.163.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 51zsj.com. 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 domain is registered through Xiamen ChinaSource Internet Service Co., Ltd (CN). It was first registered on 2007-12-03 and is set to expire on 2030-12-03, making it 18.6 years old. Our subdomain enumeration scan discovered 25 active subdomains for 51zsj.com: admin.51zsj.com, api.51zsj.com, app.51zsj.com, apps.51zsj.com, blog.51zsj.com, cdn.51zsj.com, community.51zsj.com, and dev.51zsj.com. Plus 17 additional subdomains. Active subdomains can reveal the organization's infrastructure, including development environments, API endpoints, and third-party service integrations.

The homepage of 51zsj.com contains 496 words of visible text content. This is a moderate amount of content. The page is structured with 0 H2 headings, 11 H3 headings, 0 H4 headings. The page includes 74 images. All images have proper alt text attributes ✓, which is excellent for both accessibility (screen readers) and SEO (search engines can understand image content). The link structure consists of 367 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 13 external JavaScript files, 3 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.

The title tag for 51zsj.com is good at 22 characters: "再生橡胶|再生胶厂|再生胶价格_中国再生胶网". The length is acceptable, though it may be slightly truncated in some search result displays. The meta description is 119 characters (well-optimized): "中国再生胶网提供无味再生胶,丁基再生胶,丁腈再生胶,三元乙丙再生胶,乳胶再生胶原料价格等行情资讯,注册后可发布各类再生胶产品及相关行业的供求信息,展会信息等.再生胶问答帮助橡胶精英在线交流天然胶,丁苯胶,顺丁胶,丁腈胶价格行情与橡胶配方.". 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.51zsj.com/, preventing duplicate content issues, the page language is declared as zh-cn, and a favicon is configured. No Open Graph tags are configured. When someone shares a link to 51zsj.com 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 4 terms including 再生橡胶, 再生胶厂, 再生胶价格, and 中国再生胶网. 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.