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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choosealicense.com

https://choosealicense.com· First analyzed 20 Feb 2026· Updated 20 Feb 2026

Export

choosealicense.com

Sponsored

Hosting Provider

GitHub Pages

pages.github.com

IP Address

185.199.110.153

Server Location

🇺🇸 San Francisco, United States

ASN

AS54113

Organization

GitHub, Inc

Server

GitHub.com

CDN

Fastly

Nameservers

dns4.p05.nsone.net.dns1.p05.nsone.net.dns2.p05.nsone.net.dns3.p05.nsone.net.

Performance

Page Speed

9 KB

4 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

GitHub Pages

CDN

Fastly

Technology Stack

2 Technologies Detected

CSS Frameworks

Tailwind CSS

Fonts

Google Fonts

SEO Analysis

A84/100

choosealicense.comchoosealicense.com

Choose an open source license | Choose a License

Non-judgmental guidance on choosing a license for your open source project

Title Length48 chars

Recommended: 50-60 chars

Description Length74 chars

Recommended: 120-160 chars

Issues (0)

1 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

55 URLs

robots.txt

3 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

76%Good

Static / Informational

HTTPS

No WAF

41d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

03.01.2026

Valid Until

03.04.2026

Subject Alternative Names (2)

choosealicense.comwww.choosealicense.com

SHA-256 Fingerprint

2A:75:C1:E5:42:2F:E3:07:20:B5:B6:90:88:50:FC:90:8F:44:2E:2A...

Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

access-control-allow-origin

age

cache-control

🟡 600s(max-age=600)

content-encoding

📦 Gzip(gzip)

content-length

1932

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

Domain Information

choosealicense.com

Domain Age

13y 10m

Created

16.04.2012

Expires

16.04.2027

Last Updated

15.03.2025

Registrar

MarkMonitor Inc.

DNSSEC

Not Enabled

Typography & Readability

Chivo + Helvetica Neue

87/100

Readability

/30

32/40

14px · LH 1.40

Hierarchy

/20

25/25

4.29x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

Chivo

Sans60px

Body Font

Helvetica Neue

Sans14px

Contrast Ratio

Reading Comfort

~40 CPL

Needs attention

60px

27px

22px

14px

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

✅ Optimal line spacing: 1.40 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 4.3x larger than body text.

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

⚠️ Cramped layout: 6 elements lack adequate spacing.

✅ Clean layout: Consistent center alignment throughout.

GGoogle Fonts

Sponsored

Scripts & Styles

2 Resources

Scripts

Styles

Async

Defer

Top Script Sources

Website Identity

GitHub

Sponsored

Last analyzed: 20 Feb 2026 at 11:40

Historical Analysis & Change Tracking