About this tool
Reads the DMARC policy, reporting addresses and alignment, and flags weak settings. Lookups are made live from your browser through public DNS-over-HTTPS resolvers (Cloudflare 1.1.1.1, with Google Public DNS as a fallback), so you see what the rest of the internet sees. Cached answers can be up to one TTL old.
Free to use, no sign-up. We don’t log or store what you look up.
Review your firewall rules too
Paste a config from 12 firewall platforms — plus switches, Wi-Fi, NAC, Azure NSG, NetScaler, F5 and more — and get a graded review with fix commands, mapped to 16 standards. The config never leaves your browser.
Start free See a sample report