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

yaml.org

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

Export

yaml.org

Mobile

Sponsored

Hosting Provider

GitHub Pages

pages.github.com

IP Address

185.199.109.153

Server Location

🇺🇸 San Francisco, United States

ASN

AS54113

Organization

GitHub, Inc

Server

GitHub.com

CDN

Fastly

Nameservers

evan.ns.cloudflare.com.tegan.ns.cloudflare.com.

Performance

Page Speed

338 KB

13 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

GitHub Pages

CDN

Fastly

Technology Stack

4 Technologies Detected

Other

CSS Frameworks

Icon Libraries

Fonts

SEO Analysis

D47/100

yaml.orgyaml.org

- YAML Ain't Markup Language

YAML Ain't Markup Language

Title Length28 chars

Recommended: 50-60 chars

Description Length26 chars

Recommended: 120-160 chars

Issues (1)

• Missing H1 tag - every page should have one H1

6 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

4 URLs

robots.txt

Sponsored

Security Score

21%Critical

Interactive

HTTPS

No WAF

51d

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

06.01.2026

Valid Until

06.04.2026

Subject Alternative Names (1)

yaml.org

SHA-256 Fingerprint

63:E5:86:A8:15:90:0A:CC:A8:14:DA:1A:32:4C:07:DE:1B:0F:AB:F4...

Top 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

5338

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

Domain Information

yaml.org

Domain Age

25y 1m

Created

05.01.2001

Expires

05.01.2031

Last Updated

30.05.2025

Registrar

Gandi SAS

DNSSEC

Not Enabled

Typography & Readability

-apple-system

56/100

Readability

/30

10/40

11px · LH --

Hierarchy

/20

18/25

3.2x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

-apple-system

Sans35px

Body Font

-apple-system

Sans11px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

35px

❌ Critical: 11px body text is too small. Increase to at least 14px.

✅ Strong hierarchy: Headlines are 3.2x larger than body text.

✅ Good performance: Using 1 font families keeps load times fast.

✅ Consistent design: Single font family with weight variations is a modern best practice.

✅ Clean layout: Consistent left alignment throughout.

GGoogle Fonts

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

8 Resources

Scripts

Styles

Async

Defer

Top Script Sources

assets(1)js(1)polyfill.io(1)cdn.jsdelivr.net(1)

Website Identity

X (Twitter)GitHub

Sponsored

Last analyzed: 13 Feb 2026 at 14:34

Historical Analysis & Change Tracking