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

litmus.com

https://litmus.com· First analyzed 16 Feb 2026· Updated 16 Feb 2026

Export

litmus.com

Sponsored

Hosting Provider

Pantheon

IP Address

151.101.3.52

Server Location

🇨🇦 Montreal, Canada

ASN

AS54113

Organization

Fastly, Inc.

Server

Nginx

CDN

Fastly

Nameservers

ns-251.awsdns-31.com.ns-583.awsdns-08.net.ns-1511.awsdns-60.org.ns-1844.awsdns-38.co.uk.

Performance

Page Speed

980 KB

59 requests

Image Optimization

Lazy LoadWebPResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

jQuery

Styling

Bootstrap

CMS

WordPress

Infrastructure

Hosting

Pantheon

CDN

Fastly

Technology Stack

23 Technologies Detected

Plugins

Name Directory Enlighter

Analytics

Segment Heap Analytics Microsoft Clarity

Advertising

Google Ads LinkedIn Ads Microsoft Advertising

CSS Frameworks

Libraries

Icon Libraries

Fonts

Adobe Fonts (Typekit)

Other

VWO

Web Servers

Nginx

SEO Analysis

A+94/100

litmus.comlitmus.com

All-in-One Email Marketing Platform | Tools to Drive Success

Litmus is the all-in-one email marketing platform that provides the tools and solutions your team needs to make every send count.

Title Length60 chars

Recommended: 50-60 chars

Description Length129 chars

Recommended: 120-160 chars

Issues (0)

1 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

3 URLs

robots.txt

26 rules

Sitemap reference found

Sponsored

Security Score

86%Very Good

Interactive

HTTPS

No WAF

46d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

04.01.2026

Valid Until

04.04.2026

Subject Alternative Names (2)

www-new.litmus.comwww.litmus.com

SHA-256 Fingerprint

66:9E:C0:6D:D4:E2:39:AB:9E:D0:08:28:98:FF:8A:13:70:E0:9B:99...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

age

266795

cache-control

🔵 1 Week(public, max-age=604800)

content-encoding

📦 Gzip(gzip)

content-length

59488

content-security-policy

frame-ancestors 'self' https://*.visualwebsiteoptimizer.com ...

Good Warning Issue

Email Infrastructure

Mimecast

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (2)

us-smtp-inbound-2.mimecast.com

us-smtp-inbound-1.mimecast.com

Domain Information

litmus.com

Domain Age

28y 5m

Created

25.09.1997

Expires

24.09.2026

Last Updated

23.11.2025

Registrar

1API GmbH

DNSSEC

Not Enabled

Privacy & Compliance

OneTrust

Cookie Consent Banner

OneTrust

GDPR Indicators

Cookie consent banner detected

CMP: OneTrust

Data Protection Officer mentioned

Typography & Readability

proxima-nova + sans-serif

79/100

Readability

/30

40/40

16px · LH 1.75

Hierarchy

/20

18/25

3.5x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

proxima-nova

Sans56px

Body Font

sans-serif

Sans16px

Contrast Ratio

Reading Comfort

~35 CPL

Needs attention

56px

46px

24px

16px

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

✅ Optimal line spacing: 1.75 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 3.5x larger than body text.

✅ Good performance: Using 1 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.

AAdobe Fonts Buy on MyFonts

Business & Marketing Stack

4 Tools Detected

Enterprise

Marketing Automation

MarketoEnterprise

Email marketing and automation platforms

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Privacy & Cookies

OneTrustEnterprise

Cookie consent and privacy compliance tools

A/B Testing & Optimization

VWO (Visual Website Optimizer)Mid-Market

Experimentation and conversion optimization

Sponsored

Scripts & Styles

27 Resources

Scripts

Styles

Async

Defer

Top Script Sources

litmus.com(18)js.litmuscdn.com(1)cdn.cookielaw.org(1)

Website Identity

Facebook X (Twitter)Instagram LinkedIn

Sponsored

Last analyzed: 16 Feb 2026 at 22:52

Historical Analysis & Change Tracking