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

ncbi.nlm.nih.gov

https://www.ncbi.nlm.nih.gov· First analyzed 10 Feb 2026· Updated 10 Feb 2026

Export

ncbi.nlm.nih.gov

Mobile

Sponsored

Hosting Provider

National Library of Medicine

IP Address

130.14.29.110

Server Location

🇺🇸 Kensington, United States

ASN

AS70

Organization

National Library of Medicine

Server

Apache

Nameservers

ns3.nih.gov.ns2.nih.gov.lhcns1.nlm.nih.gov.dns2-ncbi.ncbi.nlm.nih.gov.+3 more

Performance

Page Speed

503 KB

49 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

National Library of Medicine

Technology Stack

9 Technologies Detected

Analytics

CSS Frameworks

Libraries

Icon Libraries

Tag Managers

Web Servers

SEO Analysis

D41/100

www.ncbi.nlm.nih.govwww.ncbi.nlm.nih.gov

National Center for Biotechnology Information

No description available for this page.

Title Length45 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (3)

• Missing meta description - important for click-through rates
• Many images missing alt text (6/11)
• Missing viewport meta tag - page may not be mobile-friendly

7 issues found

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Sponsored

Security Score

71%Good

Interactive

HTTPS

No WAF

62d

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

accept-ranges

bytes

caf

2.0.1

content-encoding

📦 Gzip(gzip)

content-length

9144

content-security-policy

upgrade-insecure-requests

content-type

text/html

Good Warning Issue

Typography & Readability

arial + Roboto

50/100

Readability

/30

12/40

12px · LH 1.33

Hierarchy

/20

8/25

0.08x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

arial

Sans1px

Body Font

Roboto

Sans12px

Contrast Ratio

Reading Comfort

~40 CPL

Needs attention

1px

11px

14px

18px

12px

❌ Critical: 12px body text is too small. Increase to at least 14px.

⚠️ Weak hierarchy: Headlines should be at least 2x body size for clear visual structure.

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

✅ Protected text on images: Using text-shadow for readability.

Business & Marketing Stack

3 Tools Detected

Growing

Behavior Analytics

Crazy EggSMB

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

22 Resources

Scripts

Styles

Async

Defer

Top Script Sources

siteintercept.qualtrics.com(5)googletagmanager.com(3)local(3)script.crazyegg.com(2)dap.digitalgov.gov(2)

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Last analyzed: 10 Feb 2026 at 18:27

Historical Analysis & Change Tracking