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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?

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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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tldp.org

https://tldp.org· First analyzed 13 Feb 2026· Updated 13 Feb 2026

Export

tldp.org

Mobile

Sponsored

Hosting Provider

University of North Carolina at Chapel Hill

IP Address

152.19.134.161

Server Location

🇺🇸 Cary, United States

ASN

AS36850

Organization

University of North Carolina at Chapel Hill

Server

Caddy

Nameservers

b.ns.random.re.a.ns.random.re.c.ns.random.re.

Performance

Page Speed

6 KB

4 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

University of North Carolina at Chapel Hill

Technology Stack

1 Technologies Detected

Web Servers

Caddy

SEO Analysis

D41/100

tldp.orgtldp.org

The Linux Documentation Project

The Linux Documentation Project is working towards developing free, high quality documentation for the Linux operating system. The overall goal of the LDP is...

Description truncated.

Title Length31 chars

Recommended: 50-60 chars

Description Length217 chars

Recommended: 120-160 chars

Issues (2)

• Missing H1 tag - every page should have one H1
• Missing viewport meta tag - page may not be mobile-friendly

7 issues found

Upgrade to view details

Crawlability

Sitemap

robots.txt

2 rules

Sponsored

Security Score

21%Critical

Interactive

HTTPS

No WAF

74d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Google Trust Services

Key Algorithm

ECDSA (secp384r1) (384 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

29.01.2026

Valid Until

29.04.2026

OCSP Stapling

Enabled

Subject Alternative Names (4)

tldp.org*.tldp.orgtldp.net*.tldp.net

SHA-256 Fingerprint

85:6B:6F:21:30:F7:10:07:B7:7F:34:C0:8A:A5:F4:32:F7:73:D3:34...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

alt-svc

h3=":443"; ma=2592000

content-encoding

zstd

content-type

text/html; charset=utf-8

date

Fri, 13 Feb 2026 16:33:57 GMT

etag

"d5ms71putbc67s7-zstd"

last-modified

Fri, 15 Nov 2024 13:20:04 GMT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (1)

a.mx.tldp.net

Domain Information

tldp.org

Domain Age

23y 11m

Created

07.03.2002

Expires

07.03.2028

Last Updated

29.01.2026

Registrar

NameSilo, LLC

DNSSEC

Not Enabled

Typography & Readability

Times New Roman + Arial

65/100

Readability

/30

22/40

14px · LH --

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

Times New Roman

Body Font

Arial

Sans14px

Contrast Ratio

Reading Comfort

Mixed Pairing

left aligned

14px

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

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

✅ Clean layout: Consistent left alignment throughout.

Sponsored

Website Identity

GitHub

Sponsored

Last analyzed: 13 Feb 2026 at 16:34

Historical Analysis & Change Tracking