est-21.com

We performed a comprehensive analysis of est-21.com on 2026-06-30. The website returned an HTTP 200 status code with a server response time of 3802ms. The page is served over HTTP/1.1 protocol, however no compression (Gzip or Brotli) is enabled, which means the page is transferred at its full uncompressed size. The total page weight is 34 KB. The website uses a secure HTTPS connection with a valid SSL certificate issued by Let's Encrypt (DV type). The connection is encrypted using TLS 1.2 with the ECDHE-RSA-AES256-GCM-SHA384 cipher suite and sha256WithRSAEncryption signature algorithm. The certificate covers 1 domain(s) (Subject Alternative Names) and expires on 2026-09-12, which is 74 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 4 technologies across 4 categories powering est-21.com. The detected stack includes Google Tag Manager, Cloudflare, jQuery, and Font Awesome. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, est-21.com receives an overall trust score of 63/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, est-21.com 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 Let's Encrypt with 74 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 est-21.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.

Our technology detection engine scanned est-21.com and identified 4 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. Tag Manager: Google Tag Manager — manages marketing and analytics tags without code changes for est-21.com. CDN: Cloudflare — accelerates content delivery by caching assets at edge locations worldwide for est-21.com. JavaScript Library: jQuery — provides utility functions and DOM manipulation for est-21.com. Icon Set: Font Awesome — provides additional functionality for est-21.com. We also extracted the following tracking identifiers: Google Tag Manager container GTM-P35KSTW. These IDs can be used to identify other websites operated by the same organization.

est-21.com delivers its homepage in 3802ms (server response time), which is considered slow by industry standards. The total page weight is 34 KB, and we detected 215 resource requests loading assets from 13 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 est-21.com. 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 12 CSS files and 5 out of 16 JavaScript files are minified. Minifying the remaining 22 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 est-21.com produces approximately 0.02g 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 34 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for est-21.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.

est-21.com resolves to the IPv4 address 153.126.202.62, 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 4 name servers: 01.dnsv.jp, 02.dnsv.jp, 03.dnsv.jp, and 04.dnsv.jp. Having 4 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 est-21.com is handled by Google Workspace with 5 MX records configured: aspmx.l.google.com, alt1.aspmx.l.google.com, and alt2.aspmx.l.google.com and 2 more. 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 est-21.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 homepage of est-21.com contains 282 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 0 H2 headings, 3 H3 headings, 0 H4 headings. The page includes 34 images. 17 images (50%) 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 50% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 119 internal links pointing to other pages on the same domain and 5 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 16 external JavaScript files, 12 CSS stylesheets, and 4 iframes on the page. The site implements the following web standards and features: XML Sitemap (helps search engines discover all pages). Notable missing features: robots.txt 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: Instagram (@estincsaitama). An active social media presence is a positive trust indicator and helps build brand awareness and customer engagement.

The title tag for est-21.com is well-optimized at 31 characters: "埼玉の不動産投資・収益物件・建物管理｜株式会社エストハウジング". The length falls within the ideal range for Google search results, ensuring the full title is displayed without truncation. The meta description is 103 characters (well-optimized): "埼玉県・東京・千葉を中心とした首都圏の不動産投資・収益物件・建物管理のことならエストハウジングにお任せください！エストハウジングでは、購入から管理、入居者募集までをトータルにオーナー様をサポートいたします！". 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 page language is declared as ja and a favicon is configured. No Open Graph tags are configured. When someone shares a link to est-21.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 13 terms including 埼玉, 不動産投資, 収益物件, 投資物件, and 東京. 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.