404.cz

We performed a comprehensive analysis of 404.cz on 2026-06-28. The website returned an HTTP 200 status code with a server response time of 23044ms. The page is served over HTTP/2 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 49 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 100/100 (excellent). The following security headers are properly configured: Content-Security-Policy, Strict-Transport-Security (HSTS), X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. All recommended security headers are in place, providing comprehensive protection against common web attacks. Our technology detection scan identified 7 technologies across 7 categories powering 404.cz. The detected stack includes Bootstrap, Google Analytics 4, Google Tag Manager, reCAPTCHA v3, Google Fonts, jQuery 3.6.1., and Font Awesome. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, 404.cz receives an overall trust score of 70/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, 404.cz receives a trust score of 70/100, 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, and SPF (Sender Policy Framework) email authentication preventing email spoofing. Areas of concern include: 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 404.cz 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 404.cz and identified 7 distinct technologies across 7 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 404.cz. Analytics: Google Analytics 4 — tracks visitor behavior and provides traffic insights for 404.cz. Tag Manager: Google Tag Manager — manages marketing and analytics tags without code changes for 404.cz. Security: reCAPTCHA v3 — provides security features like bot detection and CAPTCHA for 404.cz. Fonts: Google Fonts — delivers web fonts for typography for 404.cz. JavaScript Library: jQuery (version 3.6.1.) — provides utility functions and DOM manipulation for 404.cz. Icon Set: Font Awesome — provides additional functionality for 404.cz. We also extracted the following tracking identifiers: Google Analytics 4 Measurement ID G-V6C02D9CTE and Google Tag Manager container GTM-PN5JMHS. These IDs can be used to identify other websites operated by the same organization.

404.cz delivers its homepage in 23044ms (server response time), which is considered slow by industry standards. The total page weight is 49 KB, and we detected 147 resource requests loading assets from 4 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: 3 out of 8 CSS files and 8 out of 15 JavaScript files are minified. Minifying the remaining 12 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 404.cz 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 49 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for 404.cz. 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.

404.cz resolves to the IPv4 address 149.62.148.11, 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: isaac.ns.cloudflare.com and sonia.ns.cloudflare.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 404.cz is handled by Google Workspace with 1 MX records configured: smtp.google.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 404.cz. 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 1 active subdomains for 404.cz: www.404.cz. Active subdomains can reveal the organization's infrastructure, including development environments, API endpoints, and third-party service integrations.

The homepage of 404.cz contains 738 words of visible text content. This is a moderate amount of content. The page is structured with 9 H2 headings, 12 H3 headings, 7 H4 headings. The page includes 58 images. 15 images (26%) 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 74% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 88 internal links pointing to other pages on the same domain and 0 external links pointing to third-party websites. There are 15 external JavaScript files, 8 CSS stylesheets, and 1 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 404.cz is well-optimized at 37 characters: "E-shop na pronájem i na míru | 404.cz". The length falls within the ideal range for Google search results, ensuring the full title is displayed without truncation. The meta description is 151 characters (well-optimized): "Spravujeme ty největší e-shopy v ČR i v zahraničí. Více než 70 % eshopů poskytovaných naší společností má roční obrat vy...". 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.404.cz/, preventing duplicate content issues, the page language is declared as cs, the meta robots directive is set to index,follow, and a favicon is configured. Open Graph meta tags are configured with 4/4 recommended fields: OG title ("404.cz..."), OG description, OG image (social sharing thumbnail), OG type (website). These tags control how the page appears when shared on Facebook, LinkedIn, and other social media platforms that support the Open Graph protocol.