indexo.dev

leapfrog.nl

.nl crawl

First seen 2026-06-02 · Last seen 2026-06-02 · ok HTTP/1.1 200 505 ms crawled 2026-06-03

NL · 85.10.159.120 · AS34762 Combell NV

Reputation 87/100 weak security headers no dmarc policy

Classifying

HTML metadata

Title
Leapfrog. Kars Alfrink's home on the web, since 2000.
Description
Dr. Kars Alfrink's personal website - Postdoctoral researcher at TU Delft focusing on contestable AI
Language
en

Technology

Server
nginx

Social

DNS records live

NS
  • ns0.transip.net
  • ns1.transip.nl
  • ns2.transip.eu
MX
  • 10 in1-smtp.messagingengine.com
  • 20 in2-smtp.messagingengine.com

Email authentication weak

SPF
v=spf1 include:spf.messagingengine.com ?all
neutral (?all)
DMARC
not published
DKIM
no key found at common selectors

Certificate (current)

R13
from 2026-04-08 to 2026-07-07
Expires in 34 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 30/100 Checked live page: https://leapfrog.nl/

findings
  • missing HSTS
  • missing Content Security Policy
  • missing frame protection
  • missing content type protection
  • missing Referrer Policy
  • missing Permissions Policy

Links to (8)

Linked from (1)