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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gocardless.com

https://gocardless.com· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

gocardless.com

Sponsored

Hosting Provider

Cloudflare

cloudflare.com

IP Address

104.16.246.239

Server Location

🇨🇦 Toronto, Canada

ASN

AS13335

Organization

Cloudflare, Inc.

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

logan.ns.cloudflare.com.april.ns.cloudflare.com.

Performance

Page Speed

1.9 MB

99 requests

Image Optimization

Lazy LoadWebPResponsive

0–49

50–89

90–100

Architecture Stack

JAMstack

⚡ SSG

Decoupled

Frontend

Framework

Gatsby

API

Data Source

Headless CMS

Contentful

Infrastructure

Hosting

Cloudflare

CDN

Cloudflare

Progressive Web App

Web ManifestApple Touch IconTheme Color

Detected API Sources

https://images.ctfassets.net/4...

Technology Stack

7 Technologies Detected

Analytics

Meta Frameworks

CSS Frameworks

Tag Managers

Customer Support

CDN

SEO Analysis

B72/100

gocardless.comgocardless.com

Online Payment Processing Solution | GoCardless

No description available for this page.

Title Length47 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (2)

• Missing meta description - important for click-through rates
• Many images missing alt text (81/107)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

1 URLs

robots.txt

2 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

86%Very Good

Interactive

HTTPS

WAF

71d

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

Valid From

30.01.2026

Valid Until

30.04.2026

OCSP Stapling

Enabled

Subject Alternative Names (1)

gocardless.com

SHA-256 Fingerprint

A0:5D:26:5E:1D:D8:41:C5:8C:E2:46:91:69:AC:42:99:A9:07:FB:32...

Upgrade to view header details

HTTP Headers

Developer Console

cache-control

🟡 1s(public,max-age=1,s-maxage=1,stale-while-revalidate=59)

cf-cache-status

EXPIRED

cf-ipcountry

cf-ray🇩🇪 Frankfurt

9cf8f5563dd818d9-FRA

client-region

content-encoding

📦 Gzip(gzip)

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (7)

aspmx3.googlemail.com

alt4.aspmx.l.google.com

aspmx.l.google.com

aspmx2.googlemail.com

+3 more

Domain Information

gocardless.com

Domain Age

26y 10m

Created

14.04.1999

Expires

14.04.2029

Last Updated

18.06.2019

Registrar

MarkMonitor Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Typography & Readability

Helvetica Neue + Haffer

80/100

Readability

/30

32/40

14px · LH 1.43

Hierarchy

/20

25/25

7.29x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Helvetica Neue

Sans102px

Body Font

Haffer

Sans14px

Contrast Ratio

Reading Comfort

~39 CPL

Needs attention

102px

14px

20px

14px

⚠️ Small text: 14px may be hard to read on mobile. Consider 16px+.

✅ Optimal line spacing: 1.43 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 7.3x 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: 38 elements lack adequate spacing.

Buy on MyFonts

Business & Marketing Stack

3 Tools Detected

Advanced

Customer Support

DriftMid-Market

Live chat and helpdesk tools

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

10 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(6)googletagmanager.com(2)js.driftt.com(1)transcend-cdn.com(1)

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Last analyzed: 17 Feb 2026 at 23:10

Historical Analysis & Change Tracking