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

cancer.gov

https://cancer.gov· First analyzed 11 Feb 2026· Updated 11 Feb 2026

Export

cancer.gov

Mobile

Sponsored

Hosting Provider

National Cancer Institute

IP Address

129.43.254.39

Server Location

🇺🇸 Frederick, United States

ASN

AS6150

Organization

National Cancer Institute

Server

Nginx

Nameservers

ns2.nih.gov.ns.nih.gov.ns3.nih.gov.

Performance

Page Speed

2.6 MB

36 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

National Cancer Institute

Technology Stack

6 Technologies Detected

Analytics

CSS Frameworks

Fonts

Web Servers

SEO Analysis

A82/100

cancer.govcancer.gov

Comprehensive Cancer Information - NCI

Accurate, up-to-date, comprehensive cancer information from the U.S. government's principal agency for cancer research.

Title Length38 chars

Recommended: 50-60 chars

Description Length119 chars

Recommended: 120-160 chars

Issues (1)

• Missing H1 tag - every page should have one H1

2 issues found

Upgrade to view details

Sponsored

Security Score

56%Poor

Interactive

HTTPS

No WAF

63d

Top Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

cache-control

🔴 No Cache(max-age=0, no-cache)

content-encoding

📦 Gzip(gzip)

content-language

content-length

10373

content-type

text/html; charset=UTF-8

Good Warning Issue

Typography & Readability

Helvetica Neue + -apple-system

71/100

Readability

/30

40/40

18px · LH 1.50

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Helvetica Neue

Sans

Body Font

-apple-system

Sans18px

Contrast Ratio

Reading Comfort

~32 CPL

Needs attention

33px

18px

✅ Excellent readability: 18px body text is ideal for all devices.

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Good performance: Using 2 font families keeps load times fast.

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

⚠️ Cramped layout: 14 elements lack adequate spacing.

✅ Clean layout: Consistent left alignment throughout.

GGoogle Fonts Buy on MyFonts

Business & Marketing Stack

3 Tools Detected

Growing

Behavior Analytics

Crazy EggSMB

Google AnalyticsFree

Google Tag ManagerFree

User behavior and product analytics

Sponsored

Scripts & Styles

16 Resources

Scripts

Styles

Async

Defer

Top Script Sources

assets.adobedtm.com(5)script.crazyegg.com(2)dap.digitalgov.gov(2)local(2)googletagmanager.com(1)

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Last analyzed: 11 Feb 2026 at 03:43

Historical Analysis & Change Tracking