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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duden.de

https://duden.de· First analyzed 15 Feb 2026· Updated 15 Feb 2026

Export

duden.de

Mobile

Sponsored

Hosting Provider

Amazon Web Services (AWS)

aws.amazon.com

IP Address

3.77.11.197

Server Location

🇩🇪 Frankfurt am Main, Germany

ASN

AS16509

Organization

AWS EC2 (eu-central-1)

CDN

Varnish

Nameservers

ns-1670.awsdns-16.co.uk.ns-1017.awsdns-63.net.ns-1096.awsdns-09.org.ns-112.awsdns-14.com.

Performance

Page Speed

530 KB

61 requests

Image Optimization

Lazy Load

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

React

CMS

Drupal

Infrastructure

Hosting

Amazon Web Services (AWS)

CDN

Varnish

Technology Stack

7 Technologies Detected

Frameworks

Libraries

CSS Frameworks

Analytics

Tag Managers

Advertising

Other

SEO Analysis

A88/100

duden.deduden.de

Duden | Sprache sagt alles.

Duden ist die Marke der deutschen Sprache ➤ Wörterbücher, Sachbücher, Ratgeber, Lernhilfen und viele digitale Produkte (Software und Apps) ➤ Duden ist mehr a...

Description truncated.

Title Length27 chars

Recommended: 50-60 chars

Description Length175 chars

Recommended: 120-160 chars

Issues (0)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

1,755 URLs

robots.txt

161 rules

Sponsored

Security Score

41%Poor

Interactive

HTTPS

No WAF

146d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Amazon

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.2

HTTP Protocol

HTTP/2

Valid From

12.06.2025

Valid Until

11.07.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

duden.de*.duden.de

SHA-256 Fingerprint

C6:09:96:DB:43:C3:ED:F9:31:66:51:1D:8B:3B:8E:C0:E8:3E:15:E4...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

accept-ranges

bytes

age

3972

cache-control

🔵 1 Days(max-age=86400, public)

content-encoding

📦 Gzip(gzip)

content-language

content-type

text/html; charset=UTF-8

Good Warning Issue

Email Infrastructure

Microsoft 365

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (1)

duden-de.mail.protection.outlook.com

Domain Information

duden.de

Last Updated

13.06.2025

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Typography & Readability

cv-linear

80/100

Readability

/30

32/40

19px · LH 1.37

Hierarchy

/20

25/25

2x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

cv-linear

Sans38px

Body Font

cv-linear

Sans19px

Contrast Ratio

Reading Comfort

~34 CPL

Needs attention

38px

37px

19px

Minor Second

Scale

✅ Excellent readability: 19px body text is ideal for all devices.

✅ Strong hierarchy: Headlines are 2.0x 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.

✅ Smart font loading: Using font-display: swap prevents invisible text during load.

⚠️ Cramped layout: 18 elements lack adequate spacing.

Buy on MyFonts

Business & Marketing Stack

3 Tools Detected

Advanced

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Privacy & Cookies

Quantcast ChoiceMid-Market

Cookie consent and privacy compliance tools

Sponsored

Scripts & Styles

18 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(7)duden.de(2)sp.duden.de(2)assets.ubembed.com(2)googletagmanager.com(1)

Website Identity

duden.de

📧 Microsoft 365

Social Profiles

Facebook Instagram LinkedIn YouTube

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Last analyzed: 15 Feb 2026 at 11:35

Historical Analysis & Change Tracking