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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jsdelivr.com

https://jsdelivr.com· First analyzed 18 Feb 2026· Updated 18 Feb 2026

Export

jsdelivr.com

Sponsored

Hosting Provider

Cloudflare

cloudflare.com

IP Address

104.21.8.91

Server Location

🇨🇦 Toronto, Canada

ASN

AS13335

Organization

Cloudflare, Inc.

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

saanvi.ns.cloudflare.com.pedro.ns.cloudflare.com.

Performance

Page Speed

486 KB

68 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

jQuery

Styling

Bootstrap

Infrastructure

Hosting

Cloudflare

CDN

Cloudflare

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

7 Technologies Detected

CSS Frameworks

Libraries

Icon Libraries

Email Marketing

Customer Support

CDN

SEO Analysis

B72/100

jsdelivr.comjsdelivr.com

jsDelivr - A free, fast, and reliable CDN for JS and open source

Optimized for JS and ESM delivery from npm and GitHub. Works with all web formats. Serving more than 150 billion requests per month.

Title Length64 chars

Recommended: 50-60 chars

Description Length132 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (76/76)

3 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

robots.txt

4 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

41%Poor

Interactive

HTTPS

WAF

38d

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

28.12.2025

Valid Until

28.03.2026

OCSP Stapling

Enabled

Subject Alternative Names (1)

www.jsdelivr.com

SHA-256 Fingerprint

C2:62:49:C9:15:56:44:83:CE:E1:88:17:CE:76:D4:85:3F:AB:9E:3F...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

age

287

cache-control

🟡 300s(public, max-age=300, must-revalidate, stale-while-revalidate...)

cf-cache-status

HIT

cf-ray🇩🇪 Frankfurt

9cf966e4693edcb9-FRA

content-encoding

zstd

content-type

text/html; charset=utf-8

Good Warning Issue

Email Infrastructure

ImprovMX

Score

SPF

DKIM

DMARC

MX Records (2)

mx1.improvmx.com

mx2.improvmx.com

Domain Information

jsdelivr.com

Domain Age

13y 9m

Created

16.05.2012

Expires

16.05.2026

Last Updated

23.01.2026

Registrar

Amazon Registrar, Inc.

DNSSEC

Not Enabled

Typography & Readability

Lexend + sans-serif

88/100

Readability

/30

40/40

16px · LH 1.50

Hierarchy

/20

25/25

2.5x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Lexend

Sans40px

Body Font

sans-serif

Sans16px

Contrast Ratio

Reading Comfort

~41 CPL

Needs attention

40px

24px

16px

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

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 2.5x larger than body text.

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

✅ Consistent design: Single font family with weight variations is a modern best practice.

✅ Protected text on images: Using gradient for readability.

Buy on MyFonts

Business & Marketing Stack

3 Tools Detected

Advanced

Marketing Automation

MailchimpSMB

Email marketing and automation platforms

Behavior Analytics

PlausibleSMB

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

15 Resources

Scripts

Styles

Async

Defer

Top Script Sources

cdn.jsdelivr.net(11)local(1)datum.jsdelivr.com(1)

Website Identity

X (Twitter)GitHub

Sponsored

Last analyzed: 18 Feb 2026 at 00:28

Historical Analysis & Change Tracking