rxjs.dev

We performed a comprehensive analysis of rxjs.dev on 2026-07-07. The website returned an HTTP 200 status code with a server response time of 1457ms. The page is served over HTTP/2 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 7 KB. The website uses a secure HTTPS connection with a valid SSL certificate issued by Google Trust Services (DV type). The connection is encrypted using TLS 1.3 with the TLS_AES_128_GCM_SHA256 cipher suite and sha256WithRSAEncryption signature algorithm. The certificate covers 100 domain(s) (Subject Alternative Names) and expires on 2026-09-22, which is 77 days from now. The security headers analysis reveals a score of 20/100 (poor). The following security headers are properly configured: Strict-Transport-Security (HSTS). However, the site is missing Content-Security-Policy, 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 6 technologies across 5 categories powering rxjs.dev. The detected stack includes React, Webpack, Google Analytics 4, Cloudflare, StackPath, and Font Awesome. The UI is built with React. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, rxjs.dev receives an overall trust score of 66/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, rxjs.dev receives a trust score of 66/100, 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, a valid SSL certificate issued by Google Trust Services with 77 days until expiration, and DNSSEC providing authenticated DNS responses. 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, and the domain's WHOIS information is hidden behind a privacy service, making it harder to verify the owner's identity. While these issues don't necessarily indicate malicious intent, they represent areas where the website's security posture could be improved. We checked rxjs.dev 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 rxjs.dev and identified 6 distinct technologies across 5 categories. This analysis is performed by examining HTTP response headers, HTML source code patterns, JavaScript library fingerprints, CSS framework signatures, and DNS records. UI Library: React — handles the user interface rendering and component management for rxjs.dev. Build Tool: Webpack — bundles and optimizes the JavaScript and CSS assets for rxjs.dev. Analytics: Google Analytics 4 — tracks visitor behavior and provides traffic insights for rxjs.dev. CDN: Cloudflare and StackPath — accelerates content delivery by caching assets at edge locations worldwide for rxjs.dev. Icon Set: Font Awesome — provides additional functionality for rxjs.dev.

rxjs.dev delivers its homepage in 1457ms (server response time), which is considered somewhat slow by industry standards. The total page weight is 7 KB, and we detected 20 resource requests loading assets from 2 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: 1 out of 3 CSS files and 0 out of 4 JavaScript files are minified. Minifying the remaining 6 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 rxjs.dev produces approximately 0.0g 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 7 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for rxjs.dev. 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.

rxjs.dev resolves to the IPv4 address 151.101.1.195, 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 2 A record(s) configured. The domain name system is managed by 4 name servers: ns-cloud-d1.googledomains.com, ns-cloud-d2.googledomains.com, ns-cloud-d3.googledomains.com, and ns-cloud-d4.googledomains.com. 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. 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 enabled for rxjs.dev, providing an additional layer of security by cryptographically signing DNS records. This prevents DNS cache poisoning and man-in-the-middle attacks that could redirect visitors to malicious websites.

The homepage of rxjs.dev contains 11 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 2 H2 headings, 0 H3 headings, 0 H4 headings. The page includes 1 image. 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 0 internal links pointing to other pages on the same domain and 0 external links pointing to third-party websites. There are 4 external JavaScript files, 3 CSS stylesheets, and 0 iframes on the page. The site implements the following web standards and features: Progressive Web App (PWA) manifest (enabling app-like installation). 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 rxjs.dev is good at 4 characters: "RxJS". The length is acceptable, though it may be slightly truncated in some search result displays. No meta description is configured for rxjs.dev. This is a critical SEO oversight — without a meta description, Google will auto-generate a snippet from page content, which may not accurately represent the page or entice users to click. Adding a unique, compelling meta description of 120-155 characters is strongly recommended. The page language is declared as en and a favicon is configured. No Open Graph tags are configured. When someone shares a link to rxjs.dev 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.