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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anthropic.com

https://anthropic.com· First analyzed 12 Feb 2026· Updated 12 Feb 2026

Export

anthropic.com

Mobile

Sponsored

Hosting Provider

Anthropic, PBC

IP Address

160.79.104.10

Server Location

🇺🇸 San Francisco, United States

ASN

AS399358

Organization

Anthropic, PBC

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

randy.ns.cloudflare.com.isla.ns.cloudflare.com.

Performance

Page Speed

76 KB

26 requests

Image Optimization

Lazy LoadWebP

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Webflow

Technology Stack

5 Technologies Detected

Other

Libraries

CSS Frameworks

CDN

SEO Analysis

C64/100

anthropic.comanthropic.com

Home \ Anthropic

Anthropic is an AI safety and research company that's working to build reliable, interpretable, and steerable AI systems.

Title Length16 chars

Recommended: 50-60 chars

Description Length121 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (1/1)

3 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

341 URLs

robots.txt

3 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

61%Fair

Interactive

HTTPS

WAF

59d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

12.01.2026

Valid Until

12.04.2026

Subject Alternative Names (1)

www.anthropic.com

SHA-256 Fingerprint

36:85:97:A9:45:F7:5D:D2:E2:60:32:0C:BB:76:8D:7A:86:A0:B9:9E...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

age

64001

alt-svc

h3=":443"; ma=86400

cf-cache-status

DYNAMIC

cf-ray🇩🇪 Frankfurt

9ccbc25c3f22db0c-FRA

content-encoding

⚡ Brotli(br)

content-security-policy

default-src 'self'; script-src 'self' 'unsafe-inline' https:...

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (5)

alt1.aspmx.l.google.com

alt4.aspmx.l.google.com

alt2.aspmx.l.google.com

aspmx.l.google.com

+1 more

Domain Information

anthropic.com

Domain Age

24y 4m

Created

02.10.2001

Expires

02.10.2033

Last Updated

09.10.2023

Registrar

MarkMonitor Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Typography & Readability

Anthropic Sans + Anthropic Serif

86/100

Readability

/30

40/40

24px · LH 1.40

Hierarchy

/20

25/25

2.67x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Anthropic Sans

Sans64px

Body Font

Anthropic Serif

Serif24px

Contrast Ratio

Reading Comfort

~42 CPL

Needs attention

64px

110px

16px

24px

✅ Excellent readability: 24px body text is ideal for all devices.

✅ Optimal line spacing: 1.40 ratio ensures comfortable reading.

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

✅ Good performance: Using 2 font families keeps load times fast.

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

⚠️ Cramped layout: 24 elements lack adequate spacing.

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

14 Resources

Scripts

Styles

Async

Defer

Top Script Sources

cdn.prod.website-files.com(7)anthropic.com(2)cdn.intellimize.co(1)cdnjs.cloudflare.com(1)d3e54v103j8qbb.cloudfront.net(1)

Website Identity

X (Twitter)LinkedIn

Sponsored

Last analyzed: 12 Feb 2026 at 11:31

Historical Analysis & Change Tracking