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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rs6.net

https://rs6.net· First analyzed 11 Feb 2026· Updated 11 Feb 2026

Export

rs6.net

Mobile

Sponsored

Hosting Provider

Constant Contact, Inc

IP Address

208.75.122.11

Server Location

🇺🇸 Waltham, United States

ASN

AS40444

Organization

Constant Contact, Inc

Server

Apache

Nameservers

dns2.p07.nsone.net.dns3.p07.nsone.net.dns4.p07.nsone.net.dns1.p07.nsone.net.

Performance

Page Speed

1 KB

3 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Constant Contact, Inc

Technology Stack

3 Technologies Detected

CSS Frameworks

Tailwind CSS

Email Marketing

Constant Contact

Web Servers

Apache

SEO Analysis

F23/100

rs6.netrs6.net

Constant Contact

No description available for this page.

Title Length16 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 (1/1)
• Missing viewport meta tag - page may not be mobile-friendly

8 issues found

Upgrade to view details

Sponsored

A+

Security Score

96%Excellent

Static / Informational

HTTPS

No WAF

38d

Upgrade to view header details

HTTP Headers

Developer Console

cache-control

🔴 No Cache(private, no-cache, no-store, max-age=0, must-revalidate, no-...)

connection

content-length

1638

content-security-policy

default-src 'self'; script-src 'self' 'unsafe-inline'; style...

content-type

text/html;charset=ISO-8859-1

date

Wed, 11 Feb 2026 07:35:28 GMT

Good Warning Issue

Typography & Readability

Helvetica Neue

87/100

Readability

/30

40/40

18px · LH 1.50

Hierarchy

/20

15/25

1.22x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

Helvetica Neue

Sans22px

Body Font

Helvetica Neue

Sans18px

Contrast Ratio

Reading Comfort

~51 CPL

Optimal (45–75)

22px

18px

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

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

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

✅ 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: ~51 characters per line is comfortable to read.

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Scripts & Styles

1 Resources

Scripts

Styles

Async

Defer

Top Script Sources

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Last analyzed: 11 Feb 2026 at 07:35

Historical Analysis & Change Tracking