indexo.dev

activecalculus.org

.org crawl

First seen 2026-04-14 · Last seen 2026-05-11 · ok HTTP/1.1 200 4234 ms crawled 2026-05-08

US · 106.0.62.83 · AS55293 A2 Hosting, Inc.

Reputation 92/100 no dmarc policy

Classifying

HTML metadata

Title
Active Calculus | Free resources for students; free and open-source materials for instructors.
Language
en-US
Generator
WordPress 6.9.4
Canonical
https://activecalculus.org/
Feeds

Technology

Server
LiteSpeed
CMS
WordPress

Third-party hosts loaded (4)

  • activecalculus.com×7
  • stats.wp.com×2
  • gmpg.org×1
  • mirrors.creativecommons.org×1

Social

Registration

Registrar
NameCheap, Inc.
Created
2017-08-17
Expires
2026-08-17 90 days left
Updated
2025-07-23
Name servers
  • ns1.a2hosting.com
  • ns2.a2hosting.com

DNS records live

NS
  • ns1.a2hosting.com
  • ns2.a2hosting.com
  • ns3.a2hosting.com
  • ns4.a2hosting.com
MX
  • 0 mail.activecalculus.org

Email authentication weak

SPF
v=spf1 +a +mx +ip4:106.0.62.83 include:spf.a2hosting.com ~all
softfail (~all)
DMARC
not published
DKIM
  • default: v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAl7aY5TDFmeWZUncaAxnYPWVTnd4Rq8kgU0nzqZ7kw0SYaRfXU5dpkh2TRjC9Rni3Bz/rzeR3yPJk9Y…
selectors probed

Certificate (current)

R13
from 2026-04-28 to 2026-07-27
Expires in 69 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 70/100 Checked live page: https://activecalculus.org/

present
  • strict-transport-security
  • x-frame-options
  • x-content-type-options
findings
  • missing Content Security Policy
  • missing Referrer Policy
  • missing Permissions Policy
Header values
x-frame-options
SAMEORIGIN
x-content-type-options
nosniff
strict-transport-security
max-age=63072000; includeSubDomains

Links to (9)

Linked from (2)