fftw.org

We performed a comprehensive analysis of fftw.org on 2026-06-30. The website returned an HTTP 200 status code with a server response time of 6334ms. The page is served over HTTP/1.1 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 13 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 5 domain(s) (Subject Alternative Names) and expires on 2026-09-16, which is 78 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 fftw.org. The detected stack includes Vite. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, fftw.org receives an overall trust score of 68/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, fftw.org receives a trust score of 68/100, 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 78 days until expiration, SPF (Sender Policy Framework) email authentication preventing email spoofing, and DMARC email authentication with a reject policy — the strongest available setting. 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 fftw.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 technology detection engine scanned fftw.org 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. Build Tool: Vite — bundles and optimizes the JavaScript and CSS assets for fftw.org.

fftw.org delivers its homepage in 6334ms (server response time), which is considered slow by industry standards. The total page weight is 13 KB, and we detected 61 resource requests loading assets from 12 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. From an environmental perspective, each page view of fftw.org 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 13 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for fftw.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.

fftw.org resolves to the IPv4 address 216.137.187.110, 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 3 name servers: ns.fftw.org, ns2.afraid.org, and puck.nether.net. Having 3 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 fftw.org is handled by fftw.org with 1 MX records configured: fftw.org. 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 (Domain-based Message Authentication, Reporting and Conformance) is configured with a reject policy — the strongest setting, instructing receiving servers to reject unauthorized emails entirely. 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 fftw.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 fftw.org contains 1,257 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 9 H2 headings, 0 H3 headings, 0 H4 headings. The page includes 3 images. 1 images (33%) 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 67% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 43 internal links pointing to other pages on the same domain and 31 external links pointing to third-party websites. There are 0 external JavaScript files, 0 CSS stylesheets, and 0 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: Github (@FFTW). An active social media presence is a positive trust indicator and helps build brand awareness and customer engagement.

The title tag for fftw.org is good at 14 characters: "FFTW Home Page". The length is acceptable, though it may be slightly truncated in some search result displays. The meta description is 130 characters (well-optimized): "A fast, free C FFT library; includes real-complex, multidimensional, and parallel transforms. Benchmarked against many o...". 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. A favicon is configured. No Open Graph tags are configured. When someone shares a link to fftw.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 9 terms including FFT, DFT, benchmark, parallel FFT, and source code. 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.