leiden.nl

We performed a comprehensive analysis of leiden.nl on 2026-07-01. The website returned an HTTP 200 status code with a server response time of 12947ms. The page is served over HTTP/2 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 33 KB. The website uses a secure HTTPS connection with a valid SSL certificate issued by DigiCert Ireland Limited (OV 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 2027-02-18, which is 232 days from now. The security headers analysis reveals a score of 85/100 (good). The following security headers are properly configured: Content-Security-Policy, Strict-Transport-Security (HSTS), X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. However, the site is missing X-Frame-Options, which could expose the site and its users to cross-site scripting (XSS), clickjacking, and other web-based attacks. Our technology detection scan identified 3 technologies across 3 categories powering leiden.nl. The detected stack includes Google Analytics 4, Google Tag Manager, and Adobe Fonts. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, leiden.nl receives an overall trust score of 82/100, classified as "Very Likely Safe".

After conducting a thorough safety and legitimacy analysis, leiden.nl receives a trust score of 82/100, which places it in the "Very 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 DigiCert Ireland Limited with 232 days until expiration, SPF (Sender Policy Framework) email authentication preventing email spoofing, DMARC email authentication with a quarantine policy, and DNSSEC providing authenticated DNS responses. Areas of concern include: no X-Frame-Options header, which could allow the site to be embedded in malicious iframes (clickjacking) 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 leiden.nl 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 leiden.nl and identified 3 distinct technologies across 3 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 leiden.nl. Tag Manager: Google Tag Manager — manages marketing and analytics tags without code changes for leiden.nl. Fonts: Adobe Fonts — delivers web fonts for typography for leiden.nl. We also extracted the following tracking identifiers: Google Tag Manager container GTM-PFMMLS. These IDs can be used to identify other websites operated by the same organization.

leiden.nl delivers its homepage in 12947ms (server response time), which is considered slow by industry standards. The total page weight is 33 KB, and we detected 54 resource requests loading assets from 5 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: 0 out of 2 CSS files and 0 out of 2 JavaScript files are minified. Minifying the remaining 4 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 leiden.nl 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 33 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for leiden.nl. 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.

leiden.nl resolves to the IPv4 address 185.144.224.28 and also supports IPv6 (2a03:9700:8000:1::25), demonstrating modern network infrastructure readiness. The domain has 3 A record(s) configured. The domain name system is managed by 3 name servers: ns1.hostingcore.nl, ns2.hostingcore.eu, and ns3.hostingcore.domains. 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 leiden.nl is handled by Microsoft 365 with 1 MX records configured: leiden-nl.mail.protection.outlook.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 (Domain-based Message Authentication, Reporting and Conformance) is configured with a quarantine policy — a moderate setting, directing unauthorized emails to spam/junk folders. DKIM was not detected. Without DKIM, recipients cannot cryptographically verify that emails claiming to be from this domain are authentic. DNSSEC is enabled for leiden.nl, 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 leiden.nl contains 87 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, 0 H3 headings, 0 H4 headings. The page includes 5 images. 4 images (80%) 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 20% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 10 internal links pointing to other pages on the same domain and 19 external links pointing to third-party websites. There are 2 external JavaScript files, 2 CSS stylesheets, and 1 iframes on the page. The site implements the following web standards and features: XML Sitemap (helps search engines discover all pages) and robots.txt (controls search engine crawling behavior). Notable missing features: Schema.org structured data. Adding these could improve search engine discoverability and rich result eligibility.

The title tag for leiden.nl is good at 26 characters: "Landingpage | Visit Leiden". The length is acceptable, though it may be slightly truncated in some search result displays. No meta description is configured for leiden.nl. 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 nl, the meta robots directive is set to all, and a favicon is configured. No Open Graph tags are configured. When someone shares a link to leiden.nl 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.