gnu.org

We performed a comprehensive analysis of gnu.org on 2026-06-29. The website returned an HTTP 200 status code with a server response time of 18216ms. The page is served over HTTP/1.1 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 31 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 1.3 with the TLS_AES_256_GCM_SHA384 cipher suite and sha256WithRSAEncryption signature algorithm. The certificate covers 34 domain(s) (Subject Alternative Names) and expires on 2026-08-07, which is 39 days from now. The security headers analysis reveals a score of 50/100 (moderate). The following security headers are properly configured: Strict-Transport-Security (HSTS), X-Frame-Options, and X-Content-Type-Options. However, the site is missing Content-Security-Policy, Referrer-Policy, and Permissions-Policy, which could expose the site and its users to cross-site scripting (XSS), clickjacking, and other web-based attacks. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, gnu.org receives an overall trust score of 69/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, gnu.org receives a trust score of 69/100, 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 a valid SSL certificate issued by Let's Encrypt with 39 days until expiration. Areas of concern include: the absence of a Content-Security-Policy header, which leaves the site more vulnerable to cross-site scripting (XSS) attacks, missing Referrer-Policy, potentially leaking URL information to third parties, 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 gnu.org 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 automated technology detection scan was unable to identify specific technologies on gnu.org. This could indicate that the site uses server-side rendering without client-side technology fingerprints, employs aggressive code obfuscation, or uses custom-built solutions that don't match known technology signatures.

gnu.org delivers its homepage in 18216ms (server response time), which is considered slow by industry standards. The total page weight is 31 KB, and we detected 166 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. 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: 2 out of 3 CSS files and 0 out of 0 JavaScript files are minified. Minifying the remaining 1 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 gnu.org 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 31 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for gnu.org. 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.

gnu.org resolves to the IPv4 address ?, 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 0 A record(s) configured. 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 gnu.org. 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 gnu.org contains 1,143 words of visible text content. This is a substantial amount of content that provides good opportunities for search engine indexing. The page is structured with 4 H2 headings, 2 H3 headings, 1 H4 headings. The page includes 12 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 86 internal links pointing to other pages on the same domain and 30 external links pointing to third-party websites. There are 0 external JavaScript files, 3 CSS stylesheets, and 0 iframes on the page. The site implements the following web standards and features: RSS feed for content syndication. 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 gnu.org is well-optimized at 55 characters: "The GNU Operating System and the Free Software Movement". The length falls within the ideal range for Google search results, ensuring the full title is displayed without truncation. The meta description is 152 characters (well-optimized): "Since 1983, developing the free Unix style operating system GNU, so that computer users can have the freedom to share an...". 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 en and a favicon is configured. No Open Graph tags are configured. When someone shares a link to gnu.org 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 12 terms including GNU, FSF, Free Software Foundation, Linux, and Emacs. 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.