indexo.dev

hypertextbook.com

.com crawl

First seen 2026-04-14 · Last seen 2026-05-15 · ok HTTP/1.1 200 3070 ms crawled 2026-05-08

US · 188.114.97.3 · AS13335 Cloudflare, Inc.

Reputation 89/100 weak security headers dmarc monitor-only

sector education type homepage

HTML metadata

Title
hypertextbook
Description
Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more.
Language
en
Canonical
https://hypertextbook.com

Open Graph

url
https://hypertextbook.com
title
hypertextbook
site name
hypertextbook.com
description
Free books to read and enjoy online. General interest hypertext-books and technical hyper-textbooks — physics, mathematics, cycling, education, media, skepticism, West Africa, and more.

Technology

CDN
Cloudflare
Analytics
  • Cloudflare Insights
  • Google Tag Manager
Fonts
  • Adobe Fonts

Third-party hosts loaded (6)

  • omniscientwalnut.com×4
  • glennelert.us×1
  • platform-api.sharethis.com×1
  • static.cloudflareinsights.com×1
  • use.typekit.net×1
  • www.googletagmanager.com×1

Registration

Registrar
eNom, LLC
Created
1999-01-26
Expires
2030-01-26 1348 days left
Updated
2021-07-29
Name servers
  • cleo.ns.cloudflare.com
  • tina.ns.cloudflare.com

DNS records live

NS
  • cleo.ns.cloudflare.com
  • tina.ns.cloudflare.com
MX
  • 0 nyc007.hawkhost.com
TXT
  • google-site-verification=HMDSfCREJrwYN7NeG97Fdh-733OIEElTx2mVO9T5B2s

Email authentication partial

SPF
v=spf1 +a +mx +ip4:172.96.186.143 +include:_spf.arandomserver.com ~all
softfail (~all)
DMARC
v=DMARC1; p=none; rua=mailto:617e21e3f35a4383a723798204f827a5@dmarc-reports.cloudflare.net
policy: none (monitoring only)
DKIM
  • default: v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAu8DJWATprn0m1hnioXH/F3tAHK1wALA2nQqmkHSR/s/hWLn1dMWQYGuOkgHeb80HmwK6Kppogs2tV3…
selectors probed

Certificate (current)

WE1
from 2026-04-08 to 2026-07-07
Expires in 49 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 30/100 Checked live page: https://hypertextbook.com/

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

Links to (1)

Linked from (3)