What does StackOptic analyze?

StackOptic runs 18 analysis modules on any public website from a single URL. It detects 7,000+ technologies (CMS, frameworks, analytics, payments, CDN, hosting), evaluates SSL certificates and HTTP security headers with grades from A+ to F, measures Core Web Vitals (LCP, CLS, TBT, FCP), audits SEO meta tags and structured data, checks email security (SPF, DKIM, DMARC), analyzes AI & LLM readiness including bot access and llms.txt validation, extracts color palettes and typography, estimates carbon footprint, and generates permanent shareable reports.

Does it work on sites behind Cloudflare or bot protection?

Yes. StackOptic uses a real browser engine that loads pages exactly like a human visitor — executing JavaScript, rendering CSS, and handling redirects. This allows it to bypass Cloudflare, LiteSpeed, Sucuri, and other bot protection systems where traditional crawlers and HTTP-only tools fail.

What do I get on the free plan?

The free plan includes 5 analyses per day with access to all 18 modules, full scores, technology detection, and security grades. Every report is permanently accessible via a unique shareable URL — no login required to view. No credit card needed. AI-powered insights, re-analysis, PDF/JSON export, and comparison features are available on Pro ($24/mo) and Agency ($99/mo) plans.

What is AI & LLM readiness analysis?

This module evaluates how visible and citable your website is to AI search engines like ChatGPT, Perplexity, Google AI Overviews, and Claude. It audits access permissions for 8 major AI bots, validates llms.txt and llms-full.txt files, scores citation-ready content structure, and analyzes structured data (JSON-LD) for GEO readiness — helping you rank in the next generation of search.

How long does an analysis take?

Most analyses complete in under 10 seconds. StackOptic runs all 18 modules in parallel using a real browser session, so you get technology detection, security audit, performance metrics, SEO analysis, and AI readiness scoring simultaneously.

How accurate are the results?

Detection is based on real browser execution — DOM inspection, JavaScript runtime analysis, HTTP headers, and DNS records. With 7,000+ technology signatures and Lighthouse-calibrated performance scoring, StackOptic achieves high accuracy for mainstream technologies.

What security checks are performed?

The security module evaluates SSL/TLS certificates, 12+ HTTP security headers (HSTS, CSP, X-Frame-Options, Permissions-Policy, Referrer-Policy), HTTPS enforcement, and email authentication (SPF, DKIM, DMARC). Each site receives a letter grade from A+ to F with specific remediation steps.

Do you store the websites I analyze?

StackOptic only stores publicly available information that any visitor to a website would see — HTML content, HTTP headers, DNS records, and screenshots. We do not access private data, log in to websites, or perform any intrusive testing.

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openstax.org

https://openstax.org· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

openstax.org

Sponsored

Hosting Provider

Amazon Web Services (AWS)

aws.amazon.com

IP Address

18.165.140.78

Server Location

🇫🇮 Helsinki, Finland

ASN

AS16509

Organization

AWS CloudFront (GLOBAL)

Server

AmazonS3

CDN

CloudFront

Nameservers

ns-602.awsdns-11.net.ns-1195.awsdns-21.org.ns-2027.awsdns-61.co.uk.ns-358.awsdns-44.com.

Performance

Page Speed

568 KB

150 requests

Image Optimization

WebP

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Amazon Web Services (AWS)

CDN

CloudFront

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

10 Technologies Detected

Analytics

Frameworks

CSS Frameworks

Icon Libraries

Tag Managers

Advertising

SEO Analysis

B76/100

openstax.orgopenstax.org

OpenStax | Free Digital Textbooks and Teaching Tools

OpenStax offers free digital textbooks and affordable teaching technology for high school and college, helping educators save time and support student success.

Title Length52 chars

Recommended: 50-60 chars

Description Length159 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (11/19)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

627 URLs

robots.txt

19 rules

Sitemap reference found

Sponsored

Security Score

71%Good

Static / Informational

HTTPS

WAF

266d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Amazon

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

12.10.2025

Valid Until

10.11.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

openstax.org*.openstax.org

SHA-256 Fingerprint

21:24:31:83:C6:D7:2B:F8:8D:BA:D4:C5:A9:33:EF:2C:33:F5:39:D0...

Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

cache-control

🟡 60s(public,max-age=60)

content-encoding

📦 Gzip(gzip)

content-type

text/html

date

Tue, 17 Feb 2026 01:24:23 GMT

etag

W/"aaef4d4cfcd4ba46fa0509eeb03dfc13"

last-modified

Tue, 16 Dec 2025 06:05:44 GMT

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (7)

aspmx.l.google.com

alt2.aspmx.l.google.com

aspmx2.googlemail.com

alt1.aspmx.l.google.com

+3 more

Domain Information

openstax.org

Domain Age

14y 4m

Created

27.09.2011

Expires

27.09.2032

Last Updated

25.06.2024

Registrar

GoDaddy.com, LLC

DNSSEC

Not Enabled

Privacy & Compliance

CookieYes

Cookie Consent Banner

CookieYes

GDPR Indicators

Cookie consent banner detected

CMP: CookieYes

Typography & Readability

Neue Helvetica W01

88/100

Readability

/30

40/40

16px · LH 1.56

Hierarchy

/20

25/25

3x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Neue Helvetica W01

Sans48px

Body Font

Neue Helvetica W01

Sans16px

Contrast Ratio

Reading Comfort

~34 CPL

Needs attention

48px

24px

16px

✅ Excellent readability: 16px body text is ideal for all devices.

✅ Optimal line spacing: 1.56 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 3.0x larger than body text.

✅ Good performance: Using 1 font families keeps load times fast.

✅ Consistent design: Single font family with weight variations is a modern best practice.

✅ Smart font loading: Using font-display: swap prevents invisible text during load.

Buy on MyFonts

Business & Marketing Stack

7 Tools Detected

Enterprise

Behavior Analytics

HotjarMid-Market

Google Tag ManagerFree

Google AnalyticsFree

Crazy EggSMB

User behavior and product analytics

Advertising

Facebook PixelMid-Market

Google AdsEnterprise

Ad platforms and retargeting pixels

Privacy & Cookies

CookieYesSMB

Cookie consent and privacy compliance tools

Sponsored

Scripts & Styles

20 Resources

Scripts

Styles

Async

Defer

Top Script Sources

googletagmanager.com(6)local(5)connect.facebook.net(2)googleads.g.doubleclick.net(2)js.pulseinsights.com(1)

Website Identity

Facebook X (Twitter)Instagram LinkedIn

Sponsored

Last analyzed: 17 Feb 2026 at 01:24

Historical Analysis & Change Tracking