NERDTOOLS / DOMAIN DIAGNOSTICS
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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.

PUBLIC ACTIVITY / WEB SCANS ONLY

What people are checking.

IncludedPublic web scans ExcludedAPI + MCP

01 / POPULAR

Leaderboard

Most scanned targets

  1. #1 google.com 2089 scans
  2. #2 nerdtools.co.uk 1751 scans
  3. #3 stiftelse-forum.se 1744 scans
  4. #4 pedago.se 1698 scans
  5. #5 joehuggans.dev 1600 scans

02 / LIVE

Recent scans

Latest public activity

  1. #1 jobbsko.se Sep 2, 05:24
  2. #2 reliancepackaging.net Sep 2, 05:10
  3. #3 chatgpt-7.se Sep 2, 04:53
  4. #4 sdransfield.co.uk Sep 2, 04:47
  5. #5 dirham.co.uk Sep 2, 04:40

Tool Detail Page

DMARC Check for fiveletters.net

Cached DMARC data found 0 DMARC records for fiveletters.net.

DMARC errors

Cached Tool Summary

Cached DMARC data found 0 DMARC records for fiveletters.net.

Last cached scan: 2026-09-02 03:50 UTC

Key Facts

  • DMARC records: 0
  • Policy: not detected
  • DMARC host: _dmarc.fiveletters.net

Key Findings

  • No DMARC record found. Publish a TXT record at _dmarc.fiveletters.net starting with v=DMARC1.
Full scan page Canonical public report for fiveletters.net. 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.

Full API + MCP coverage: Every read-only diagnostic is available on Free and Pro. Plans differ by quota and rate limits.

Explore the developer platform 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
  • 29 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: complete diagnostic catalog
Get a free key
FOR PRODUCTION

PRO

£19 / monthly

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

  • 10,000 requests / month
  • 60 requests / minute
  • REST + MCP: complete diagnostic catalog
Start with Pro

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04 / COVERAGE

29 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