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Free tools

Email and IP intelligence, free to try.

A small set of focused tools built on the same versioned dataset that powers the LimesIndex API. No signup required for a quick look.

Header Lab

Paste raw email headers and trace delivery hop by hop.

Reconstruct the full delivery path of any message, with IP enrichment per hop and an at-a-glance summary of authentication results.

  • Hop-by-hop IP enrichment with ASN, geo, and reputation
  • SPF, DKIM, and DMARC parsing with pass/fail reasoning
  • Latency between relays surfaced inline
  • Shareable result links for incident reviews
Try Header Lab

Domain Health

A through F grade for any sending domain.

Check SPF, DKIM, and DMARC posture in one pass and get a prioritized list of fixes ranked by deliverability impact.

  • Single-letter grade derived from auth posture
  • SPF lookup count, includes, and overflow warnings
  • DKIM selector discovery with key strength checks
  • DMARC policy guidance and rollout recommendations
Grade a Domain

IP Lookup

Instant context for any IPv4 or IPv6 address.

Threat scoring, RPKI validity, geolocation, and ASN reputation in a single response. Built on the same versioned dataset that powers the API.

  • RPKI ROA validity and origin AS verification
  • Multi-source geo consensus with confidence
  • ASN reputation, ownership history, and abuse signals
  • Versioned answers so caches and clients stay in sync
Look Up an IP

AI Crawler Firewall

Block GPTBot, ClaudeBot, and friends in one copy-paste.

Generate ready-to-paste blocking rules from the LimesIndex AI crawler dataset. Pick your stack, optionally narrow to a single vendor, copy the snippet — done.

  • nginx deny directives, Caddyfile @blocked matchers
  • iptables/ip6tables shell script with v4 and v6
  • Cloudflare WAF Custom Rule expression
  • Per-vendor filter for GPTBot, ClaudeBot, PerplexityBot, and more
Block AI Crawlers

More tools on the way

ASN Health is next: peering posture, RPKI coverage, and reputation trends for any autonomous system. Want to be told when it ships? Open the dashboard and we will keep you posted.