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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english-heritage.org.uk

https://english-heritage.org.uk· First analyzed 13 Feb 2026· Updated 13 Feb 2026

Export

Mobile

Sponsored

Hosting Provider

Episerver Stockholm

IP Address

217.114.94.2

Server Location

🇸🇪 Stockholm, Sweden

ASN

AS30811

Organization

Episerver Stockholm

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

ns3-05.azure-dns.org.ns4-05.azure-dns.info.ns1-05.azure-dns.com.ns2-05.azure-dns.net.

Performance

Page Speed

4.4 MB

84 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Optimizely CMS (Episerver)

Technology Stack

13 Technologies Detected

Analytics

Google Analytics

Google Analytics 4

Matomo Microsoft Clarity

Advertising

Google Ads Microsoft Advertising

Frameworks

Libraries

UI Components

CSS Frameworks

Fonts

Tag Managers

CDN

SEO Analysis

B76/100

english-heritage.org.ukenglish-heritage.org.uk

English Heritage | English Heritage

English Heritage cares for over 400 historic places, bringing the story of England to life for millions of visitors each year.

Title Length35 chars

Recommended: 50-60 chars

Description Length126 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (17/19)

3 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

6,956 URLs

robots.txt

5 rules

Allows all crawlers

Sponsored

Security Score

36%Critical

Interactive

HTTPS

WAF

45d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Google Trust Services

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-256

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

31.12.2025

Valid Until

31.03.2026

OCSP Stapling

Enabled

Subject Alternative Names (1)

www.english-heritage.org.uk

SHA-256 Fingerprint

B4:38:E9:08:5A:21:95:85:0E:82:AE:AD:1A:EE:51:56:0A:89:CC:10...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

alt-svc

h3=":443"; ma=86400

cache-control

🟡 3097s(public, max-age=3097)

cf-cache-status

DYNAMIC

cf-ray🇩🇪 Frankfurt

9cd7e7246f1edcc5-FRA

content-encoding

📦 Gzip(gzip)

content-type

text/html; charset=utf-8

Good Warning Issue

Email Infrastructure

Microsoft 365

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (1)

englishheritage-org-uk01i.mail.protection.outlook.com

Domain Information

english-heritage.org.uk

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Typography & Readability

moderne-medium + moderne-regular

56/100

Readability

/30

40/40

18px · LH 1.60

Hierarchy

/20

18/25

2.66x ratio

WCAG

/25

5/15

Contrast: undefined

Performance

/25

10/20

3 fonts

Heading Font

moderne-medium

Sans48px

Body Font

moderne-regular

Sans18px

Contrast Ratio

Reading Comfort

~34 CPL

Needs attention

48px

32px

24px

18px

✅ Excellent readability: 18px body text is ideal for all devices.

✅ Optimal line spacing: 1.60 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 2.7x larger than body text.

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

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

⚠️ Cramped layout: 63 elements lack adequate spacing.

Buy on MyFonts

Business & Marketing Stack

5 Tools Detected

Enterprise

Behavior Analytics

Microsoft ClarityFree

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Advertising

Microsoft AdsEnterprise

Ad platforms and retargeting pixels

Privacy & Cookies

Quantcast ChoiceMid-Market

Cookie consent and privacy compliance tools

Sponsored

Scripts & Styles

23 Resources

Scripts

Styles

Async

Defer

Top Script Sources

googletagmanager.com(5)local(5)bat.bing.com(2)cdn.cookie-script.com(2)scripts.clarity.ms(1)

Website Identity

Facebook X (Twitter)Instagram YouTube

Sponsored

Last analyzed: 13 Feb 2026 at 22:54

Historical Analysis & Change Tracking