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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cervantes.es

https://cervantes.es· First analyzed 14 Feb 2026· Updated 14 Feb 2026

Export

cervantes.es

Mobile

Sponsored

Hosting Provider

Red del Instituto Cervantes

IP Address

193.146.5.10

Server Location

🇪🇸 Alcalá de Henares, Spain

ASN

AS766

Organization

Red del Instituto Cervantes

Server

Apache

Nameservers

dns.cervantes.es.machuca.cervantes.es.

Performance

Page Speed

2.1 MB

66 requests

Image Optimization

Lazy LoadWebP

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

jQuery

Styling

Tailwind CSS

Infrastructure

Hosting

Red del Instituto Cervantes

Technology Stack

9 Technologies Detected

CSS Frameworks

Analytics

Libraries

Icon Libraries

Fonts

Tag Managers

Web Servers

SEO Analysis

B76/100

cervantes.escervantes.es

Instituto Cervantes

Nuevo sitio web oficial del Instituto Cervantes, la institución pública española para promover la enseñanza, el aprendizaje y el uso del español y difundir l...

Description truncated.

Title Length19 chars

Recommended: 50-60 chars

Description Length223 chars

Recommended: 120-160 chars

Issues (0)

3 issues found

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Crawlability

Sitemap

robots.txt

53 rules

Sponsored

Security Score

41%Poor

Interactive

HTTPS

No WAF

234d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Sectigo Limited

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

Valid From

30.09.2025

Valid Until

06.10.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.cervantes.orgcervantes.org

SHA-256 Fingerprint

C3:9B:4E:92:46:7B:2D:CB:6D:DB:1C:E7:E7:C4:66:07:C2:76:EC:CB...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

cache-control

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

content-encoding

📦 Gzip(gzip)

content-language

content-length

27596

content-type

text/html; charset=UTF-8

date

Sat, 14 Feb 2026 04:21:19 GMT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (3)

cervantes-mxbck.sistemaip.net

vela2.cervantes.es

vela1.cervantes.es

Domain Information

cervantes.es

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Typography & Readability

dmsans

68/100

Readability

/30

32/40

34px · LH 1.24

Hierarchy

/20

15/25

0.29x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

dmsans

Sans10px

Body Font

dmsans

Sans34px

Contrast Ratio

Reading Comfort

~42 CPL

Needs attention

10px

56px

32px

34px

✅ Excellent readability: 34px body text is ideal for all devices.

⚠️ 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.

⚠️ Cramped layout: 44 elements lack adequate spacing.

GGoogle Fonts 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

30 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(11)googletagmanager.com(5)cdn.jsdelivr.net(3)google-analytics.com(1)

Website Identity

Facebook X (Twitter)LinkedIn

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Last analyzed: 14 Feb 2026 at 04:22

Historical Analysis & Change Tracking