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

check24.de

https://check24.de· First analyzed 19 Feb 2026· Updated 19 Feb 2026

Export

check24.de

Sponsored

Hosting Provider

CHECK24 GmbH

IP Address

195.30.64.1

Server Location

🇩🇪 Ismaning, Germany

ASN

AS5539

Organization

CHECK24 GmbH

Server

Nginx

Nameservers

ns15.digicertdns.net.ns12.digicertdns.com.ns11.digicertdns.com.ns13.digicertdns.net.+2 more

Performance

Page Speed

4 MB

106 requests

Image Optimization

Lazy LoadWebP

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

React

Infrastructure

Hosting

CHECK24 GmbH

Technology Stack

10 Technologies Detected

UI Components

Frameworks

Libraries

CSS Frameworks

Icon Libraries

Analytics

Tag Managers

Web Servers

Customer Support

SEO Analysis

D55/100

check24.decheck24.de

CHECK24 | Das Vergleichsportal

No description available for this page.

Title Length30 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (3)

• Missing meta description - important for click-through rates
• Missing H1 tag - every page should have one H1
• Many images missing alt text (20/20)

4 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

13 URLs

robots.txt

30 rules

Sitemap reference found

Sponsored

Security Score

56%Poor

Interactive

HTTPS

No WAF

73d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

ZeroSSL

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

02.02.2026

Valid Until

03.05.2026

OCSP Stapling

Enabled

Subject Alternative Names (1)

www.check24.de

SHA-256 Fingerprint

5C:86:1B:53:06:D4:CD:BF:35:8E:CC:D1:17:0B:08:85:C4:CF:28:DE...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

cache-control

🔴 No Cache(no-store, no-cache, must-revalidate)

content-encoding

📦 Gzip(gzip)

content-security-policy

frame-ancestors check24.de *.check24.de

content-type

text/html; charset=UTF-8

date

Thu, 19 Feb 2026 22:14:15 GMT

expires

Mon, 26 Jul 1997 05:00:00 GMT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (3)

mail1.o.check24.de

mail2.o.check24.de

mail3.o.check24.de

Domain Information

check24.de

Last Updated

22.05.2025

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Data Protection Officer mentioned

Typography & Readability

Verdana

41/100

Readability

/30

12/40

12px · LH 1.33

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Verdana

Sans

Body Font

Verdana

Sans12px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

18px

15px

12px

Major Second

Scale

❌ Critical: 12px body text is too small. Increase to at least 14px.

✅ 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: 7 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

Advertising

Microsoft AdsEnterprise

Ad platforms and retargeting pixels

Sponsored

Scripts & Styles

15 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(12)googletagmanager.com(1)chat.bot.check24.de(1)check24.de(1)

Website Identity

Facebook Instagram TikTok

Sponsored

Last analyzed: 19 Feb 2026 at 22:14

Historical Analysis & Change Tracking