Server, DNS & Technology Checkers
These checkers look at the infrastructure behind a page: which server and CDN answer, whether HTTP/2 or HTTP/3 is negotiated, what DNS returns, how old the domain is and which CMS, frameworks, analytics and tracking tags the page loads.
Most are diagnostic rather than ranking-related. They help explain slow responses, migration problems or missing analytics.
Facebook Pixel Checker
Detects a Facebook Pixel (and other tracking pixels) on the page.
Analytics Checker
Detects Google Analytics or another web-analytics tool on the page.
Built With Checker
Detects the CMS, frameworks, CDN and other technology a site is built with.
Character Encoding Checker
Reports the charset the page declares.
Website DNS Lookup
Resolves the A, AAAA and NS records for a domain to show where it points.
Website IP Address Finder
Finds the IPv4 and IPv6 addresses a domain resolves to.
Web Server Checker
Identifies the web server software and CDN powering a site.
HTTP/2 Usage Checker
Checks whether the origin negotiates HTTP/2 (or HTTP/3) via ALPN.
ads.txt Validator
Checks each line of ads.txt has the required domain, account id and relationship fields.
Ping Tester
Queries the site and reports whether it responded and how long it took.
Domain Age Checker
Looks up when the domain was registered via RDAP (the public WHOIS successor).