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.

Back to Search

purl.org

https://purl.org· First analyzed 11 Feb 2026· Updated 11 Feb 2026

Export

purl.org

Mobile

Sponsored

Hosting Provider

Internet Archive

IP Address

207.241.225.157

Server Location

🇺🇸 San Francisco, United States

ASN

AS7941

Organization

Internet Archive

Server

Nginx

Nameservers

motorhead.easydns.org.rush.easydns.com.nirvana.easydns.net.

Performance

Page Speed

299 KB

6 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

jQuery

Styling

Bootstrap

Infrastructure

Hosting

Internet Archive

Technology Stack

4 Technologies Detected

CSS Frameworks

Libraries

Web Servers

SEO Analysis

F35/100

purl.orgpurl.org

PURL Administration

No description available for this page.

Title Length19 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (2)

• Missing meta description - important for click-through rates
• Many images missing alt text (1/1)

7 issues found

Upgrade to view details

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Security Score

21%Critical

Interactive

HTTPS

No WAF

33d

Top Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

connection

keep-alive

content-encoding

📦 Gzip(gzip)

content-type

text/html; charset=utf-8

date

Wed, 11 Feb 2026 07:30:28 GMT

server

nginx

transfer-encoding

chunked

Good Warning Issue

Typography & Readability

Helvetica Neue

88/100

Readability

/30

32/40

14px · LH 1.43

Hierarchy

/20

21/25

2.57x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

Helvetica Neue

Sans36px

Body Font

Helvetica Neue

Sans14px

Contrast Ratio

Reading Comfort

~45 CPL

Optimal (45–75)

36px

18px

14px

⚠️ Small text: 14px may be hard to read on mobile. Consider 16px+.

✅ Optimal line spacing: 1.43 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 2.6x larger than body text.

✅ Excellent performance: System fonts eliminate font loading delays (better LCP).

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

✅ Optimal line length: ~45 characters per line is comfortable to read.

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Scripts & Styles

5 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(3)

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Last analyzed: 11 Feb 2026 at 07:31

Historical Analysis & Change Tracking