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

sixt.com

https://sixt.com· First analyzed 20 Feb 2026· Updated 20 Feb 2026

Export

sixt.com

Sponsored

Hosting Provider

Amazon Web Services (AWS)

aws.amazon.com

IP Address

52.223.9.45

Server Location

🇨🇦 Montreal, Canada

ASN

AS16509

Organization

AWS Global Accelerator (GLOBAL)

Server

nginorange

CDN

CloudFront

Nameservers

d.ns14.net.c.ns14.net.b.ns14.net.

Performance

Page Speed

2.3 MB

250 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Amazon Web Services (AWS)

CDN

CloudFront

Technology Stack

5 Technologies Detected

Other

Other

CSS Frameworks

Analytics

Tag Managers

SEO Analysis

A88/100

sixt.comsixt.com

Premium Car Rental at affordable prices | SIXT rent a car

Car rental deals on premium cars & other like-new rentals ✓2,000+ rental car locations ✓no hidden costs ✓pay later option ➤Rent a car easily online

Title Length57 chars

Recommended: 50-60 chars

Description Length147 chars

Recommended: 120-160 chars

Issues (0)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

1 URLs

robots.txt

9 rules

Sitemap reference found

Sponsored

Security Score

66%Fair

Interactive

HTTPS

No WAF

81d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Amazon

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

12.04.2025

Valid Until

12.05.2026

OCSP Stapling

Enabled

Subject Alternative Names (1)

www.sixt.com

SHA-256 Fingerprint

DD:70:12:C1:B9:C2:30:10:C8:24:AD:E1:7B:DF:C6:B4:94:5C:21:1A...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

age

182

alt-svc

h3=":443"; ma=86400

cache-control

🟡 600s(max-age=600,public)

content-encoding

⚡ Brotli(br)

content-type

text/html

date

Fri, 20 Feb 2026 07:53:40 GMT

Good Warning Issue

Email Infrastructure

Microsoft 365

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (1)

sixt-com.mail.protection.outlook.com

Domain Information

sixt.com

Domain Age

28y 7m

Created

22.07.1997

Expires

21.07.2026

Last Updated

22.07.2025

Registrar

InterNetX GmbH

DNSSEC

Not Enabled

Privacy & Compliance

Usercentrics

Cookie Consent Banner

Usercentrics

GDPR Indicators

Cookie consent banner detected

CMP: Usercentrics

Data Protection Officer mentioned

Typography & Readability

HelveticaNow

75/100

Readability

/30

40/40

16px · LH 1.50

Hierarchy

/20

15/25

1x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

HelveticaNow

Sans16px

Body Font

HelveticaNow

Sans16px

Contrast Ratio

Reading Comfort

~34 CPL

Needs attention

16px

60px

30px

16px

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

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

⚠️ Weak hierarchy: Headlines should be at least 2x body size for clear visual structure.

✅ Good performance: Using 2 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.

Buy on MyFonts

Business & Marketing Stack

2 Tools Detected

Growing

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

11 Resources

Scripts

Styles

Async

Defer

Top Script Sources

web.cmp.usercentrics.eu(7)local(3)eum.instana.io(1)

Website Identity

Instagram LinkedIn

Sponsored

Last analyzed: 20 Feb 2026 at 07:56

Historical Analysis & Change Tracking