NERDTOOLS / DOMAIN DIAGNOSTICS

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DOMAIN INTELLIGENCE WEB · REST · MCP

Know what a domain is telling you.

One diagnostic surface for DNS, email, TLS, security, availability and SEO. Scan now, then put structured DNS and email signals inside your product or AI agent.

Run a free scan Build with the API

01 / DIAGNOSE

Start with a domain or public IP.

Hide results ? When enabled, this scan will not appear in the most recent searches or the scan leaderboard.

Scan leaderboard

Most searched domains and IPs.

  1. #1 google.com 2083 scans
  2. #2 nerdtools.co.uk 1748 scans
  3. #3 stiftelse-forum.se 1743 scans
  4. #4 pedago.se 1697 scans
  5. #5 joehuggans.dev 1599 scans

Most recent scans

Latest searches across the toolset.

  1. #1 millenniumgroup.co.uk Sep 1, 15:14
  2. #2 openheart.co.uk Sep 1, 15:14
  3. #3 ircakansai.net Sep 1, 15:13
  4. #4 rensai.net Sep 1, 15:13
  5. #5 badgesolutions.co.uk Sep 1, 15:13

Tool Detail Page

LLMs.txt Check for openheart.co.uk

Cached llms.txt data did not find a usable /llms.txt file for openheart.co.uk.

llms.txt missing

Cached Tool Summary

Cached llms.txt data did not find a usable /llms.txt file for openheart.co.uk.

Last cached scan: 2026-08-31 16:19 UTC

Key Facts

  • Title: missing
  • Sections: 0
  • Links: 0

Key Findings

  • llms.txt was found, but it is empty.
  • No top-level Markdown title was found.
  • No Markdown links were found in llms.txt.
Full scan page Canonical public report for openheart.co.uk. Blacklist Check Supporting detail view for the canonical scan page. CAA Check Supporting detail view for the canonical scan page. DMARC Check Supporting detail view for the canonical scan page. Domain Expiry Check Supporting detail view for the canonical scan page. DKIM Check Supporting detail view for the canonical scan page. DNS Lookup Supporting detail view for the canonical scan page. DNSSEC Check Supporting detail view for the canonical scan page. IP Info Supporting detail view for the canonical scan page. IP Reputation Supporting detail view for the canonical scan page. MX Check Supporting detail view for the canonical scan page. LLMs.txt Check Supporting detail view for the canonical scan page. Robots.txt Checker Supporting detail view for the canonical scan page. Redirect Check Supporting detail view for the canonical scan page. SEO Check Supporting detail view for the canonical scan page. Ping Supporting detail view for the canonical scan page. Port Scan Supporting detail view for the canonical scan page. SPF Check Supporting detail view for the canonical scan page. SSL Certificate Check Supporting detail view for the canonical scan page. TLS Protocol Check Supporting detail view for the canonical scan page. Security Headers Check Supporting detail view for the canonical scan page. Security.txt Check Supporting detail view for the canonical scan page. Sitemap Checker Supporting detail view for the canonical scan page. WHOIS Lookup Supporting detail view for the canonical scan page.

02 / INTEGRATE

From one-off diagnosis to in-product intelligence.

The browser is for investigation. The API and MCP server are for repeatable workflows—monitoring domains, enriching customer data, validating email setup, and giving agents reliable DNS tools.

Read the API reference Create a developer account
REST / V1MCP / HTTPONLINE
GET /api/v1/email/dmarc
  ?domain=example.com

Authorization: Bearer nt_live_…

200  { "ok": true,
       "data": { "policy": "reject" } }

Same key. Same quota. Structured JSON for software and agents.

03 / ACCESS

Start free. Pay when diagnostics become infrastructure.

WEB SCAN

£0 / open access

For individual investigations and shareable public reports.

  • Full browser diagnostic
  • No registration required
  • 28 focused checks
Run a scan

DEVELOPER FREE

£0 / developer

For testing the REST API and MCP server in real workflows.

  • 100 requests / day
  • 10 requests / minute
  • REST + MCP access
Get a free key
FOR PRODUCTION

PRO

See checkout / monthly

For products, automations and agents that depend on domain signals.

  • 10,000 requests / month
  • 60 requests / minute
  • Stripe-managed billing
Start with Pro

The exact Pro price is confirmed before checkout. No charge is made until you approve it.

04 / COVERAGE

Twenty-eight checks. One diagnostic surface.

Inspect the whole domain or go directly to a single signal.

Website Down Detector WHOIS Lookup Domain Expiry Checker DNS Lookup Tool DNSSEC Checker SSL Certificate Checker TLS Protocol Checker Security Headers Checker Redirect Checker SEO Check Tool SPF Record Checker DMARC Record Checker DKIM Record Checker CAA Record Checker MX Record Checker Blacklist Check IP Info Lookup IP Reputation Check Online Ping Tool Online Port Scanner Robots.txt Checker Security.txt Checker LLMs.txt Checker XML Sitemap Checker Schema Markup Tester Meta Tag & Open Graph Preview Broken Link Checker Core Web Vitals Quick Check Indexation Checker