Tools
Free domain hygiene checks — ten dossier checks plus context lookups. No signup. Also callable over MCP.
Want all eighteen in one shareable report? Run the domain dossier →
DNS
Email auth
Transport
Web security
- security headers checker
inspect the response headers served at https://<domain>/ — HSTS, CSP, X-Frame-Options, etc.
- cors checker
run a CORS preflight (OPTIONS) against a domain and surface the access-control-* response headers.
- web surface inspector
fetch robots.txt, sitemap.xml, and the home page's <head> to summarise a domain's public-web surface.
Domain context
Auxiliary lookups for geolocation, request fingerprinting, and single-record DNS — not part of the dossier engine, but useful when investigating a finding.
- user agent
parse your browser's user agent string (browser, os, device, engine).
- what is my ip
your public ip address, location, and timezone.
- http headers
inspect the http request headers your browser sends.
- ip lookup
look up any IP's geolocation, ASN, and ISP (via ipinfo.io).
- dns lookup
resolve A, AAAA, MX, TXT, NS, or CNAME records via Cloudflare DoH.
- blacklist check
check whether a domain's web and mail server IPs are on email blocklists (Barracuda, SpamCop, UCEPROTECT, Mailspike, PSBL, s5h).
- dmarc record generator
build a valid DMARC TXT record from your policy, reporting addresses and alignment — with warnings for the mistakes people make.
- spf record generator
build a valid SPF TXT record from your includes, IPs and qualifier — with a live count of the 10-DNS-lookup limit.