theorie.nl

We performed a comprehensive analysis of theorie.nl on 2026-06-30. The website returned an HTTP 200 status code with a server response time of 19062ms. The page is served over HTTP/2 protocol with Gzip compression enabled, achieving approximately 60.0% size reduction. The total page weight is 126 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_128_GCM_SHA256 cipher suite and sha256WithRSAEncryption signature algorithm. The certificate covers 1 domain(s) (Subject Alternative Names) and expires on 2026-08-31, which is 62 days from now. The security headers analysis reveals a score of 60/100 (moderate). The following security headers are properly configured: X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. However, the site is missing Content-Security-Policy and Strict-Transport-Security (HSTS), which could expose the site and its users to cross-site scripting (XSS), clickjacking, and other web-based attacks. Our technology detection scan identified 2 technologies across 2 categories powering theorie.nl. The detected stack includes Angular and Google Tag Manager. The site uses Angular as its primary framework. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, theorie.nl receives an overall trust score of 80/100, classified as "Very Likely Safe".

After conducting a thorough safety and legitimacy analysis, theorie.nl receives a trust score of 80/100, 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, a valid SSL certificate issued by Let's Encrypt with 62 days until expiration, SPF (Sender Policy Framework) email authentication preventing email spoofing, DMARC email authentication with a reject policy — the strongest available setting, 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 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 theorie.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 theorie.nl and identified 2 distinct technologies across 2 categories. This analysis is performed by examining HTTP response headers, HTML source code patterns, JavaScript library fingerprints, CSS framework signatures, and DNS records. Framework: Angular — provides the application framework and routing for theorie.nl. Tag Manager: Google Tag Manager — manages marketing and analytics tags without code changes for theorie.nl. We also extracted the following tracking identifiers: Google Tag Manager container GTM-K9CXR7. These IDs can be used to identify other websites operated by the same organization.

theorie.nl delivers its homepage in 19062ms (server response time), which is considered slow by industry standards. The total page weight is 126 KB, and we detected 268 resource requests loading assets from 9 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 1 CSS files and 0 out of 3 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 theorie.nl produces approximately 0.06g 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 126 KB is the primary factor in this calculation. Core Web Vitals data from the Chrome User Experience Report (CrUX) is not available for theorie.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.

theorie.nl resolves to the IPv4 address 52.18.136.112, 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: nsn1.mijndomein.nl and nsn2.mijndomein.nl. 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 theorie.nl is handled by mijndomein.nl with 2 MX records configured: mx1.mijndomein.nl and mx2.mijndomein.nl. 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 enabled for theorie.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 theorie.nl contains 4,613 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 17 H2 headings, 33 H3 headings, 10 H4 headings. The page includes 45 images. 37 images (82%) 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 18% of images have proper alt text — we recommend adding descriptive alt attributes to all images. The link structure consists of 77 internal links pointing to other pages on the same domain and 57 external links pointing to third-party websites. There are 3 external JavaScript files, 1 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), Schema.org structured data (AggregateRating, Brand, BreadcrumbList, ContactPoint, ImageObject, ListItem, LocalBusiness, Offer, OpeningHoursSpecification, Organization, PostalAddress, Product, and WebSite), and Progressive Web App (PWA) manifest (enabling app-like installation). Notable missing features: robots.txt. Adding these could improve search engine discoverability and rich result eligibility. We detected the following payment methods accepted on theorie.nl: Visa, Mastercard, and Apple Pay. Offering multiple payment options including credit cards and digital wallets improves customer trust and can increase conversion rates. The website has social media presence across 3 platforms: Instagram (@theorie.nl), Linkedin (@theorie.nl-b.v.), and Tiktok (@theorienl). An active social media presence is a positive trust indicator and helps build brand awareness and customer engagement.

The title tag for theorie.nl is well-optimized at 60 characters: "Theorie.nl | Oefen en leer online voor je CBR theorie examen". The length falls within the ideal range for Google search results, ensuring the full title is displayed without truncation. The meta description is 137 characters (well-optimized): "Leer en oefen online voor je CBR theorie-examen met onze online videocursus en oefenexamens. Wij helpen kandidaten al 25...". 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.theorie.nl/, preventing duplicate content issues, the page language is declared as nl-nl, the meta robots directive is set to max-image-preview:large, and a favicon is configured. Open Graph meta tags are configured with 4/4 recommended fields: OG title ("Oefen en leer online voor je CBR theorie examen..."), 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. A Twitter Card of type summary_large_image is configured, which controls how links appear when shared on Twitter/X. The "summary_large_image" type displays a large image preview, which typically generates higher engagement rates than the basic card type. The site implements Schema.org structured data with the following types: AggregateRating, Brand, BreadcrumbList, ContactPoint, ImageObject, ListItem, LocalBusiness, Offer, OpeningHoursSpecification, Organization, PostalAddress, Product, and WebSite. Structured data helps search engines understand the page content and can enable rich results (featured snippets, knowledge panels, star ratings) in Google search results, which can significantly increase click-through rates.