Category
DNS & network diagnostics
See this section on the full toolbox page alongside every other category.
DNS lookup
A, AAAA, MX, TXT, NS, CNAME and CAA records for a domain.
DNS & network diagnosticsEmail deliverability checker
Look up and validate a domain's SPF, DKIM and DMARC records.
DNS & network diagnosticsHTTP header inspector
See response headers, status code and the redirect chain.
DNS & network diagnosticsSecurity headers checker
Grade a site's CSP, HSTS and other security headers.
DNS & network diagnosticsPort checker
Check whether a host:port is open.
DNS & network diagnosticsWhat's my IP
Shows the IP address this server sees for you.
DNS & network diagnosticsIPv4 address converter
Convert an IPv4 address between dotted-decimal, hex, binary and integer.
DNS & network diagnosticsCIDR range expander
Expand a CIDR block into its full IP range, or the reverse.
DNS & network diagnosticsMAC address lookup
Look up the hardware vendor for a MAC address.
DNS & network diagnosticsMAC address generator
Generate random MAC addresses, valid or locally-administered.
DNS & network diagnosticsIP geolocation lookup
Look up the approximate location and ISP for an IP address.
DNS & network diagnosticsCORS checker
Test whether a URL sends proper cross-origin headers for a given origin.
DNS & network diagnosticsWebsite speed checker
Measure connect time, time to first byte, and total load time.
DNS & network diagnosticsEmail header analyzer
Parse raw email headers and trace the delivery hops.