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

circle.com

https://circle.com· First analyzed 20 Feb 2026· Updated 20 Feb 2026

Export

circle.com

Sponsored

Hosting Provider

Cloudflare

cloudflare.com

IP Address

104.16.30.32

Server Location

🇨🇦 Toronto, Canada

ASN

AS13335

Organization

Cloudflare, Inc.

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

ns1.circle.com.ns2.circle.com.

Performance

Page Speed

89 KB

62 requests

Image Optimization

Lazy LoadWebPAVIFResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Cloudflare

CDN

Cloudflare

Technology Stack

9 Technologies Detected

Analytics

Libraries

Other

UI Components

CSS Frameworks

Tag Managers

Marketing

CDN

SEO Analysis

A+94/100

circle.comcircle.com

Circle | Open infrastructure for faster, smarter payments

Circle (NYSE: CRCL) enables businesses to leverage digital currencies and public blockchains for payments, commerce and financial applications worldwide.

Title Length57 chars

Recommended: 50-60 chars

Description Length153 chars

Recommended: 120-160 chars

Issues (0)

1 issues found

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Crawlability

Sitemap

Type: standard

1,236 URLs

robots.txt

76 rules

Sitemap reference found

Sponsored

Security Score

56%Poor

Interactive

HTTPS

WAF

246d

Certificate Details

Type

Extended Validation (EV)

Certificate Authority

DigiCert Inc

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

23.09.2025

Valid Until

24.10.2026

OCSP Stapling

Enabled

Subject Alternative Names (6)

circle.comwww.circle.comapi.circle.compay.circle.cominvest.circle.comusdc.circle.com

SHA-256 Fingerprint

53:7C:01:A0:39:16:CB:DC:E8:7B:F6:BD:CD:CC:7C:77:91:79:F7:08...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

age

cf-cache-status

HIT

cf-ray🇩🇪 Frankfurt

9d0adab7aeca3a8e-FRA

content-encoding

📦 Gzip(gzip)

content-security-policy

frame-ancestors 'self'

content-type

text/html; charset=utf-8

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

100

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (2)

mxa-00400e02.gslb.pphosted.com

mxb-00400e02.gslb.pphosted.com

Domain Information

circle.com

Domain Age

26y 10m

Created

09.04.1999

Expires

09.04.2026

Last Updated

06.03.2025

Registrar

Gandi SAS

DNSSEC

Not Enabled

Privacy & Compliance

OneTrust

Cookie Consent Banner

OneTrust

GDPR Indicators

Cookie consent banner detected

CMP: OneTrust

Legitimate interest basis mentioned

Typography & Readability

Circularxx

84/100

Readability

/30

40/40

16px · LH 1.50

Hierarchy

/20

21/25

5x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Circularxx

Sans80px

Body Font

Circularxx

Sans16px

Contrast Ratio

Reading Comfort

~43 CPL

Needs attention

80px

51px

16px

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

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 5.0x 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.

Buy on MyFonts

Business & Marketing Stack

4 Tools Detected

Enterprise

CRM Systems

HubSpotMid-Market

Customer Relationship Management platforms

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Privacy & Cookies

OneTrustEnterprise

Cookie consent and privacy compliance tools

Sponsored

Scripts & Styles

22 Resources

Scripts

Styles

Async

Defer

Top Script Sources

cdn.prod.website-files.com(6)cdnjs.cloudflare.com(4)googletagmanager.com(2)tools.refokus.com(2)cdn.cookielaw.org(1)

Website Identity

circle.com

26 years old

Gandi SAS

Social Profiles

X (Twitter)Instagram LinkedIn YouTube Discord

Sponsored

Last analyzed: 20 Feb 2026 at 03:18

Historical Analysis & Change Tracking