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

lulus.com

https://lulus.com· First analyzed 19 Feb 2026· Updated 19 Feb 2026

Export

lulus.com

Mobile

Sponsored

Hosting Provider

Fastly, Inc.

IP Address

151.101.1.151

Server Location

🇨🇦 Montreal, Canada

ASN

AS54113

Organization

Fastly, Inc.

Server

Varnish

CDN

Fastly

Nameservers

ns-956.awsdns-55.net.ns-1116.awsdns-11.org.ns-1885.awsdns-43.co.uk.ns-398.awsdns-49.com.

Performance

Page Speed

311 KB

15 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Fastly, Inc.

CDN

Fastly

Technology Stack

2 Technologies Detected

Fonts

Google Fonts

Caching

Varnish

SEO Analysis

F35/100

lulus.comlulus.com

Access to this page has been denied

px-captcha

Title Length35 chars

Recommended: 50-60 chars

Description Length10 chars

Recommended: 120-160 chars

Issues (1)

• Missing H1 tag - every page should have one H1

6 issues found

Upgrade to view details

Crawlability

Sitemap

robots.txt

30 rules

Sitemap reference found

Sponsored

Security Score

36%Critical

Interactive

HTTPS

No WAF

188d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Sectigo Limited

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

06.08.2025

Valid Until

26.08.2026

OCSP Stapling

Enabled

Subject Alternative Names (10)

www.lulus.comcheckout.lulus.comfashion.lulus.comlulus.comluluserv.comlulusfashionlounge.comm.lulus.comsearch.lulus.com+2 more

SHA-256 Fingerprint

47:92:33:77:CD:FF:1C:53:95:F3:05:AB:EF:22:B8:6D:30:CA:5A:41...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

server

Varnish

retry-after

content-type

text/html

accept-ranges

bytes

date

Thu, 19 Feb 2026 19:30:27 GMT

set-cookie

_pxhd

Good Warning Issue

Email Infrastructure

Microsoft 365

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (1)

lulus-com.mail.protection.outlook.com

Domain Information

lulus.com

Domain Age

30y 5m

Created

12.09.1995

Expires

11.09.2031

Last Updated

12.08.2024

Registrar

GoDaddy.com, LLC

DNSSEC

Not Enabled

Typography & Readability

serif

71/100

Readability

/30

30/40

16px · LH --

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

serif

Body Font

serif

Serif16px

Contrast Ratio

Reading Comfort

Single Family

center aligned

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

✅ Excellent performance: System fonts eliminate font loading delays (better LCP).

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

4 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(1)client.px-cloud.net(1)lulus.com(1)

Sponsored

Last analyzed: 19 Feb 2026 at 19:30

Historical Analysis & Change Tracking