NerdTools Fast, free online tools for sysadmins, developers, and nerds.

Domain Scan URL Shortener Tools About

Scan any domain or IP in seconds.

Run WHOIS, DNS, SSL, security headers, blacklist checks, and more from a single interface. No registration required.

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 1897 scans
  2. #2 nerdtools.co.uk 1627 scans
  3. #3 stiftelse-forum.se 1590 scans
  4. #4 pedago.se 1537 scans
  5. #5 joehuggans.dev 1464 scans

Most recent scans

Latest searches across the toolset.

  1. #1 anguston.co.uk Aug 13, 15:10
  2. #2 timothyhardie.co.uk Aug 13, 15:10
  3. #3 van-mourik.org Aug 13, 15:10
  4. #4 idahofoodbankfund.org Aug 13, 15:10
  5. #5 hustolk.se Aug 13, 15:10

Tool Detail Page

DMARC Check for netdef.org

Cached DMARC data found 0 DMARC records for netdef.org.

DMARC errors

Cached Tool Summary

Cached DMARC data found 0 DMARC records for netdef.org.

Last cached scan: 2026-08-13 12:58 UTC

Key Facts

  • DMARC records: 0
  • Policy: not detected
  • DMARC host: _dmarc.netdef.org

Key Findings

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

Why NerdTools?

Everything in one place

Stop juggling browser tabs. Run WHOIS, DNS, SSL, security headers, blacklist checks, and more from a single page.

Built for speed

Results load fast. No sign-up walls, no waiting around. Just enter a domain and go.

Free to use

Core scans are completely free. Short links are available when you need them.

Explore every tool

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