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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fosdem.org

https://fosdem.org· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

fosdem.org

Sponsored

Hosting Provider

TIG HDC Fosdem

IP Address

31.22.22.140

Server Location

🇧🇪 Brussels, Belgium

ASN

AS56837

Organization

TIG HDC Fosdem

Server

Nginx

Nameservers

ns5.he.net.ns1.fosdem.org.ns2.fosdem.org.ns1.x-net.be.

Performance

Page Speed

668 KB

12 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

TIG HDC Fosdem

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

3 Technologies Detected

Meta Frameworks

Astro

CSS Frameworks

Tailwind CSS

Web Servers

Nginx

SEO Analysis

D52/100

fosdem.orgfosdem.org

FOSDEM 2026 - Home

No description available for this page.

Title Length18 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (1)

• Missing meta description - important for click-through rates

6 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

2,474 URLs

robots.txt

Sponsored

Security Score

76%Good

Interactive

HTTPS

No WAF

70d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (3072 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

29.01.2026

Valid Until

29.04.2026

Subject Alternative Names (2)

fosdem.orgwww.fosdem.org

SHA-256 Fingerprint

8D:D9:43:D6:90:48:AC:6F:33:6C:6F:8C:7D:23:A1:C8:0A:68:9A:2B...

Top Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

cache-control

🟡 300s(max-age=300)

content-encoding

📦 Gzip(gzip)

content-security-policy

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

content-type

text/html; charset=utf-8

date

Tue, 17 Feb 2026 21:14:10 GMT

expires

Tue, 17 Feb 2026 21:19:10 GMT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

MX Records (1)

mail.fosdem.org

Domain Information

fosdem.org

Domain Age

24y 8m

Created

22.06.2001

Expires

22.06.2027

Last Updated

12.01.2026

Registrar

Key-Systems GmbH

DNSSEC

Not Enabled

Typography & Readability

Signika + DejaVu Sans

78/100

Readability

/30

32/40

14px · LH 1.40

Hierarchy

/20

25/25

2.75x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Signika

Sans39px

Body Font

DejaVu Sans

Sans14px

Contrast Ratio

Reading Comfort

~42 CPL

Needs attention

39px

32px

16px

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 2.8x larger than body text.

✅ Good performance: Using 2 font families keeps load times fast.

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

⚠️ Cramped layout: 24 elements lack adequate spacing.

Buy on MyFonts

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Scripts & Styles

1 Resources

Scripts

Styles

Async

Defer

Top Script Sources

Sponsored

Last analyzed: 17 Feb 2026 at 21:14

Historical Analysis & Change Tracking