cnx.org
OpenStax | Free online textbooks, affordable learning technology, and open educational resources
Last scanned Jul 22, 2026, 5:57 PM · 1 view
Overall score
Great
Summary
OpenStax is the world’s largest publisher of open education resources (OER) and a provider of integrated learning technologies and education research for high school and college. This website uses Google Analytics hosted on AWS behind CloudFront CDN. SEO is good (80/100) and accessibility is excellent (100/100). Security scores fair (65/100) and performance good (85/100). Top issue: Title longer than 60 characters.
OpenStax is the world’s largest publisher of open education resources (OER) and a provider of integrated learning technologies and education research for high school and college. We are a global nonprofit at Rice University.
- United States
- Hosted on AWS
Top issues to fix
8 issues found · 2 high priority
Missing Strict-Transport-Security header
SecurityAdd HSTS so browsers always use HTTPS — this closes the protocol-downgrade attack window.
Missing Content-Security-Policy header
SecurityAdd a CSP to control which sources can run scripts — the strongest single defense against XSS.
Missing X-Content-Type-Options header
SecurityAdd X-Content-Type-Options: nosniff to stop MIME-sniffing attacks.
Missing X-Frame-Options header
SecurityAdd X-Frame-Options (or a CSP frame-ancestors rule) to prevent clickjacking via hidden iframes.
Title longer than 60 characters
SEOShorten the title to under 60 characters so search results don't truncate it.
Meta description longer than 160 characters
SEOTrim the meta description to under 160 characters to avoid truncation in search results.
+2 more issues — details in the sections below.
SEO
3 issue(s) found
Performance
9 ms
Security
HTTPS & header checks
Accessibility
0 issue(s) found
Organization
Company details published in this site's own structured data.
Contact
Email, phone, and address published on this site's own pages.
Source: https://openstax.org/contact
Meta tags
- Title
- OpenStax | Free online textbooks, affordable learning technology, and open educational resources
- Description
- OpenStax is the world’s largest publisher of open education resources (OER) and a provider of integrated learning technologies and education research for high school and college. We are a global nonprofit at Rice University.
- Canonical
- https://openstax.org
- Language
- en-US
- Charset
- utf-8
- Viewport
- width=device-width,initial-scale=1,maximum-scale=5
- Robots meta
- Manifest
- https://openstax.org/dist/assets/manifest.webmanifest
Technologies
Detected frameworks, languages, and tools.
Hosting & CDN
- Hosting provider
- AWS
- CDN provider
- CloudFront
- IP address
- 18.172.78.5
- ASN
- AS16509 (AMAZON-02 - Amazon.com, Inc., US)
DNS records
| Type | Value |
|---|---|
| A |
|
| AAAA | — |
| MX |
|
| TXT | — |
| NS |
|
| CAA | — |
| CNAME | — |
| IPv6 support | No |
TLS / SSL certificate
- Version
- TLS 1.3
- Issuer
- Amazon
- Subject
- openstax.org
- Valid from
- Oct 12, 2025
- Valid to
- Nov 10, 2026
- Days until expiry
- 111
- SAN domains
- openstax.org, *.openstax.org
Security headers
- Strict-Transport-SecurityMissing
- Content-Security-PolicyMissing
- X-Frame-OptionsMissing
- X-Content-Type-OptionsMissing
- Referrer-PolicyMissing
- Permissions-PolicyMissing
Compression: gzip · 0 cookie(s) observed
Content & assets
Headings
H1 1 · H2 9 · H3 7
Links
39 internal · 16 external · 1 broken
Images
22 total · 0 missing alt
Scripts / Styles
28 scripts · 0 stylesheets
JS / CSS size
1.1 MB · 191 KB
Page size
12.1 KB
Robots.txt & Sitemap
- robots.txt
- Found
- Disallow rules
- 15
- sitemap.xml
- Found
- URLs in sitemap
- 388
SEO issues
- Title longer than 60 characters
- Meta description longer than 160 characters
- No structured data (JSON-LD) found
Accessibility issues
No accessibility issues detected.
Careers
This company has an active careers page, but individual openings weren't reliably parsed from it — visit the page above for current listings.
Scan details
- Requested URL
- https://cnx.org
- Final URL
- https://openstax.org
- HTTP status
- 200
- HTTP version
- HTTP/2
- Response time
- 9 ms
- HTML size
- 12.1 KB
- Redirect chain
- https://cnx.org → https://openstax.org
See something wrong on this report? Request a correction
Related websites
Same technology stack
exxonmobil.com
Exxon Mobil Corporation | ExxonMobil
opera.com
Opera Web Browser | Faster, Safer, Smarter | Opera
barracudanetworks.com
Cybersecurity Solutions: Email, Apps, Network, Data | Barracuda Networks
walmart.ca
Online Shopping Canada: Everyday Low Prices at Walmart.ca!
semrush.com
Semrush: Your Unfair Advantage for Growing Brand Visibility
userway.org
UserWay | Web Accessibility Solutions
Same hosting provider
natural.com
Natural — Powering agentic payments
flippingbook.com
FlippingBook | Flipbook Maker for Digital Publishing
opera.com
Opera Web Browser | Faster, Safer, Smarter | Opera
monaco.com
Monaco – The first revenue engine for startups
ghost.org
Ghost: The best open source blog & newsletter platform
zen.co.uk
Top Rated Home & Business Broadband Providers | Zen Internet
Frequently asked questions
- What technology does cnx.org use?
- cnx.org is built with Google Analytics, Meta Pixel.
- Is cnx.org secure (HTTPS)?
- Yes. cnx.org uses TLS 1.3 with a certificate issued by Amazon, valid until Nov 10, 2026.
- Who hosts cnx.org?
- cnx.org is hosted on AWS, behind CloudFront CDN.
- What is cnx.org's SEO score?
- cnx.org scored 80/100 for SEO in the latest analysis (great).
- What is cnx.org's overall website score?
- cnx.org has an overall SiteGraph score of 82/100, combining SEO, performance, security, and accessibility.
- Is cnx.org hiring?
- cnx.org has a careers page; check it directly for current openings.
OpenGraph & Twitter Card
OpenGraph
Twitter Card