numberplace.net

We performed a comprehensive analysis of numberplace.net on 2026-06-30. The website returned an HTTP 200 status code with a server response time of 7951ms. 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 27 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 2 domain(s) (Subject Alternative Names) and expires on 2026-09-21, which is 83 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 1 technologies across 1 categories powering numberplace.net. The detected stack includes Google Analytics 4. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, numberplace.net receives an overall trust score of 60/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, numberplace.net 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, a valid SSL certificate issued by Let's Encrypt with 83 days until expiration, and a well-established domain registered for over 15.5 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 numberplace.net 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 GMO Internet Group, Inc. d/b/a Onamae.com based in JP, with a registration date of 2010-12-20 and expiration date of 2026-12-20.

Our technology detection engine scanned numberplace.net and identified 1 distinct technologies across 1 categories. This analysis is performed by examining HTTP response headers, HTML source code patterns, JavaScript library fingerprints, CSS framework signatures, and DNS records. Analytics: Google Analytics 4 — tracks visitor behavior and provides traffic insights for numberplace.net. We also extracted the following tracking identifiers: Google Analytics 4 Measurement ID G-2JN4ZG1ZSR. These IDs can be used to identify other websites operated by the same organization.

numberplace.net delivers its homepage in 7951ms (server response time), which is considered slow by industry standards. The total page weight is 27 KB, and we detected 62 resource requests loading assets from 6 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 numberplace.net. 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: 0 out of 2 CSS files and 0 out of 9 JavaScript files are minified. Minifying the remaining 11 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 numberplace.net produces approximately 0.01g 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 27 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for numberplace.net. 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.

numberplace.net resolves to the IPv4 address 153.122.170.37, 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.domainking.cloud and ns2.domainking.cloud. 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 numberplace.net is handled by numberplace.net with 1 MX records configured: mail.numberplace.net. Multiple MX records provide failover redundancy — if the primary mail server is unavailable, email will be routed to the next available server. SPF is not configured, meaning any server could potentially send emails pretending to be from this domain. This is a significant email security concern. 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 numberplace.net. 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 GMO Internet Group, Inc. d/b/a Onamae.com (JP). It was first registered on 2010-12-20 and is set to expire on 2026-12-20, making it 15.5 years old. Our subdomain enumeration scan discovered 2 active subdomains for numberplace.net: mail.numberplace.net and www.numberplace.net. Active subdomains can reveal the organization's infrastructure, including development environments, API endpoints, and third-party service integrations.

The homepage of numberplace.net contains 62 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 1 H2 headings, 5 H3 headings, 4 H4 headings, 3 H5, and 0 H6 headings. The page includes 22 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 26 internal links pointing to other pages on the same domain and 1 external link pointing to third-party websites. There are 9 external JavaScript files, 2 CSS stylesheets, and 1 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: Twitter (@num20_JP). An active social media presence is a positive trust indicator and helps build brand awareness and customer engagement.

The title tag for numberplace.net is well-optimized at 30 characters: "ナンプレ20 - 無料数独問題集 sudoku for PC". The length falls within the ideal range for Google search results, ensuring the full title is displayed without truncation. The meta description is 63 characters (acceptable): "毎日20問、無料でナンプレ（数独）をブラウザでオンラインプレイできます。面倒なダウンロード・インストールや登録は一切不要です。". 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 numberplace.net 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.