indexo.dev

tel4u.org

.org crawl

First seen 2026-04-20 · Last seen 2026-05-11 · ok HTTP/1.1 200 1019 ms crawled 2026-05-14

US · 69.32.208.200 · AS27365 Cengage Learning, Inc.

Reputation 100/100

Classifying

HTML metadata

Title
Tel4U
Description
TEL4u - A Universe of Free Resources for Grades K-5
Language
en

Technology

Server
Apache

Third-party hosts loaded (6)

  • assets.gale.com×11
  • cdn.jsdelivr.net×7
  • assets.cengage.com×4
  • cdnjs.cloudflare.com×2
  • code.jquery.com×2
  • www.gstatic.com×1

Registration

Registrar
Key-Systems GmbH
Created
2011-01-03
Expires
2028-01-03 592 days left
Updated
2026-05-10
Name servers
  • dns1.p01.nsone.net
  • dns2.p01.nsone.net
  • dns3.p01.nsone.net
  • dns4.p01.nsone.net

DNS records live

NS
  • ns1x.cengage.net
  • ns2x.cengage.net

Email authentication no MX

SPF
v=spf1 -all
strict (-all)
DMARC
not published
DKIM
no key found at common selectors

Certificate (current)

Sectigo Public Server Authentication CA OV R36
from 2025-12-15 to 2027-01-12
Expires in 236 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 50/100 Checked live page: https://tel4u.org/

present
  • strict-transport-security
findings
  • missing Content Security Policy
  • missing frame protection
  • missing content type protection
  • missing Referrer Policy
  • missing Permissions Policy
Header values
strict-transport-security
max-age=31536000; includeSubDomains

Links to (2)

Linked from (1)