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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irfanview.com

https://irfanview.com· First analyzed 13 Feb 2026· Updated 13 Feb 2026

Export

irfanview.com

Mobile

Sponsored

Hosting Provider

Host Europe GmbH

IP Address

92.204.31.110

Server Location

🇬🇧 Slough, United Kingdom

ASN

AS21499

Organization

Host Europe GmbH

Server

Apache

Nameservers

ns35.domaincontrol.com.ns36.domaincontrol.com.

Performance

Page Speed

173 KB

13 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Host Europe GmbH

Technology Stack

2 Technologies Detected

CSS Frameworks

Tailwind CSS

Web Servers

Apache

SEO Analysis

D56/100

irfanview.comirfanview.com

IrfanView - Official Homepage - One of the Most Popular Viewers Wor...

IrfanView ... one of the most popular viewers worldwide.

Title truncated.

Title Length73 chars

Recommended: 50-60 chars

Description Length56 chars

Recommended: 120-160 chars

Issues (0)

7 issues found

Upgrade to view details

Crawlability

Sitemap

robots.txt

3 rules

Sponsored

Security Score

81%Very Good

Static / Informational

HTTPS

No WAF

338d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Starfield Technologies, Inc.

Key Algorithm

RSA (4096 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.2

HTTP Protocol

HTTP/2

Valid From

18.12.2025

Valid Until

17.01.2027

OCSP Stapling

Enabled

Subject Alternative Names (2)

www.irfanview.comirfanview.com

SHA-256 Fingerprint

31:EC:66:AD:98:05:C1:4C:CD:12:AB:EF:21:8E:73:E1:FD:D6:BD:04...

Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

content-encoding

⚡ Brotli(br)

content-length

2485

content-type

text/html

date

Fri, 13 Feb 2026 23:32:07 GMT

etag

"21400ee-2fb3-647f75763a690-br"

Good Warning Issue

Email Infrastructure

Microsoft 365

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (1)

irfanview-com.mail.protection.outlook.com

Domain Information

irfanview.com

Domain Age

26y 1m

Created

06.01.2000

Expires

06.01.2027

Last Updated

05.01.2026

Registrar

Mesh Digital Limited

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Typography & Readability

Arial

45/100

Readability

/30

32/40

29px · LH 1.20

Hierarchy

/20

8/25

0.83x ratio

WCAG

/25

5/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

Arial

Sans24px

Body Font

Arial

Sans29px

Contrast Ratio

Reading Comfort

~33 CPL

Needs attention

24px

16px

18px

16px

29px

✅ Excellent readability: 29px body text is ideal for all devices.

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

✅ Excellent performance: System fonts eliminate font loading delays (better LCP).

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

⚠️ Risky: Text appears on background images without overlay protection.

⚠️ Cramped layout: 6 elements lack adequate spacing.

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

1 Resources

Scripts

Styles

Async

Defer

Top Script Sources

Sponsored

Last analyzed: 13 Feb 2026 at 23:32

Historical Analysis & Change Tracking