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10 utilities
Domain & Diagnostics
URL, DNS, subnet, headers, and host diagnostics you can run without handing us a log.
URL Parser
Split a URL into protocol, host, path, query, and hash.
HTTP Status Reference
Look up status codes and their meaning.
DNS Lookup (DoH)
Resolve records via Cloudflare DNS only after you click Run.
Subnet / CIDR Calculator
Compute network, mask, range, and host counts.
User-Agent Inspector
Parse this browser’s user agent locally.
SPF / DMARC Draft
Draft SPF and DMARC TXT record templates.
TLS Checklist
A local pre-flight checklist for certificate health.
Domain & IP Validator
Validate hostnames and IPv4 / IPv6 formats.
Security Header Draft
Draft CSP, HSTS, and related response headers.
Query String Builder
Compose and decode URL query parameters.