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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3sat.de

https://3sat.de· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

3sat.de

Mobile

Sponsored

Hosting Provider

ZDF Zweites Deutsches Fernsehen

IP Address

91.197.29.51

Server Location

🇩🇪 Mainz, Germany

ASN

AS43354

Organization

ZDF Zweites Deutsches Fernsehen

Nameservers

a1-107.akam.net.a10-64.akam.net.a9-66.akam.net.a22-67.akam.net.+4 more

Performance

Page Speed

561 KB

13 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

ZDF Zweites Deutsches Fernsehen

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

2 Technologies Detected

Meta Frameworks

Astro

CSS Frameworks

Tailwind CSS

SEO Analysis

B78/100

3sat.de3sat.de

Startseite - 3sat-Mediathek

Videos und Livestreams in der 3satMediathek anschauen! Entdecken Sie Dokumentationen, Magazine aus Kultur, Wissenschaft, Gesellschaft und vieles mehr!

Title Length27 chars

Recommended: 50-60 chars

Description Length150 chars

Recommended: 120-160 chars

Issues (1)

• Missing H1 tag - every page should have one H1

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

3 URLs

robots.txt

1 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

21%Critical

Interactive

HTTPS

No WAF

176d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

DigiCert Inc

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

13.08.2025

Valid Until

12.08.2026

OCSP Stapling

Enabled

Subject Alternative Names (20)

www.zdf.de*.3sat.de*.heute.de*.logo.de*.phoenix.de*.sc.zdf.de*.tivi.de*.zdf.de+12 more

SHA-256 Fingerprint

7B:25:0E:76:55:1D:1A:28:B7:59:1F:35:E1:45:5B:A1:12:7D:8C:2A...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

cache-control

🟡 24s(max-age=24)

content-encoding

📦 Gzip(gzip)

content-language

content-type

text/html;charset=UTF-8

date

Tue, 17 Feb 2026 04:02:10 GMT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (1)

mail.zdf.de

Domain Information

3sat.de

Last Updated

26.09.2024

DNSSEC

Not Enabled

Privacy & Compliance

OneTrust

Cookie Consent Banner

OneTrust

GDPR Indicators

Cookie consent banner detected

CMP: OneTrust

Typography & Readability

3satHurme

71/100

Readability

/30

40/40

16px · LH 1.50

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

3satHurme

Sans

Body Font

3satHurme

Sans16px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

16px

24px

18px

16px

Major Second

Scale

✅ Excellent readability: 16px body text is ideal for all devices.

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

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

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

⚠️ Cramped layout: 47 elements lack adequate spacing.

✅ Clean layout: Consistent left alignment throughout.

Buy on MyFonts

Business & Marketing Stack

2 Tools Detected

Advanced

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Privacy & Cookies

OneTrustEnterprise

Cookie consent and privacy compliance tools

Sponsored

Scripts & Styles

5 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(2)cmp2.3sat.de(1)3sat.de(1)

Website Identity

Instagram YouTube

Sponsored

Last analyzed: 17 Feb 2026 at 04:02

Historical Analysis & Change Tracking