sumatrapdfreader.org

We performed a comprehensive analysis of sumatrapdfreader.org on 2026-06-30. The website returned an HTTP 200 status code with a server response time of 28412ms. The page is served over HTTP/2 protocol, however no compression (Gzip or Brotli) is enabled, which means the page is transferred at its full uncompressed size. The total page weight is 31 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_256_GCM_SHA384 cipher suite and ECDSA-SHA256 signature algorithm. The certificate covers 1 domain(s) (Subject Alternative Names) and expires on 2026-09-21, which is 83 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 sumatrapdfreader.org. The detected stack includes Svelte. The site uses Svelte as its primary framework. Based on our comprehensive analysis of domain age, SSL configuration, email authentication, security headers, and blacklist status, sumatrapdfreader.org receives an overall trust score of 63/100, classified as "Likely Safe".

After conducting a thorough safety and legitimacy analysis, sumatrapdfreader.org receives a trust score of 63/100, 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 Google Trust Services with 83 days until expiration, and SPF (Sender Policy Framework) email authentication preventing email spoofing. 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 sumatrapdfreader.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 sumatrapdfreader.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. Framework: Svelte — provides the application framework and routing for sumatrapdfreader.org.

sumatrapdfreader.org delivers its homepage in 28412ms (server response time), which is considered slow by industry standards. The total page weight is 31 KB, and we detected 63 resource requests loading assets from 6 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. No compression is currently enabled on sumatrapdfreader.org. Enabling Brotli or Gzip compression could reduce page size by 60-80% for text-based assets (HTML, CSS, JavaScript), significantly improving load times and reducing bandwidth costs. This is one of the simplest and most impactful performance optimizations available. Asset minification status: 0 out of 1 CSS files and 0 out of 2 JavaScript files are minified. Minifying the remaining 3 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 sumatrapdfreader.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 sumatrapdfreader.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.

sumatrapdfreader.org resolves to the IPv4 address 216.24.57.1, 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: gail.ns.cloudflare.com and terry.ns.cloudflare.com. 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 sumatrapdfreader.org is handled by cloudflare.net with 3 MX records configured: route2.mx.cloudflare.net, route3.mx.cloudflare.net, and route1.mx.cloudflare.net. 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 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 sumatrapdfreader.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 sumatrapdfreader.org contains 527 words of visible text content. This is a moderate amount of content. The page is structured with 3 H2 headings, 0 H3 headings, 0 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 22 internal links pointing to other pages on the same domain and 13 external links pointing to third-party websites. There are 2 external JavaScript files, 1 CSS stylesheets, and 0 iframes on the page. The site implements the following web standards and features: XML Sitemap (helps search engines discover all pages), robots.txt (controls search engine crawling behavior), and Schema.org structured data (Answer, FAQPage, Offer, Question, and SoftwareApplication). The website has social media presence across 2 platforms: Twitter (@Merjia_) and Github (@sumatrapdfreader). An active social media presence is a positive trust indicator and helps build brand awareness and customer engagement.

The title tag for sumatrapdfreader.org is well-optimized at 47 characters: "Sumatra PDF — Free, Fast PDF Reader for Windows". The length falls within the ideal range for Google search results, ensuring the full title is displayed without truncation. The meta description is 141 characters (well-optimized): "Download Sumatra PDF — a free, fast, lightweight PDF reader for Windows. Supports PDF, EPUB, MOBI, CBZ, DjVu, XPS, and C...". 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.sumatrapdfreader.org/free-pdf-reader, preventing duplicate content issues, the page language is declared as en, and a favicon is configured. Open Graph meta tags are configured with 4/4 recommended fields: OG title ("Sumatra PDF — Free, Fast PDF Reader for Windows..."), 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: Answer, FAQPage, Offer, Question, and SoftwareApplication. 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.