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

costco.com

https://costco.com· First analyzed 13 Feb 2026· Updated 13 Feb 2026

Export

costco.com

Mobile

Sponsored

Hosting Provider

Akamai Technologies

IP Address

88.221.170.96

Server Location

🇩🇪 Frankfurt am Main, Germany

ASN

AS16625

Server

Envoy

CDN

Akamai

WAF

Akamai

Nameservers

a6-64.akam.net.a14-67.akam.net.a5-64.akam.net.a28-66.akam.net.+2 more

Performance

Page Speed

1.3 MB

132 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Hybrid

🔀 Hybrid

Frontend

Framework

Next.js

Infrastructure

Hosting

Akamai Technologies

CDN

Akamai

Technology Stack

9 Technologies Detected

Meta Frameworks

CSS Frameworks

Frameworks

Fonts

Advertising

Customer Support

Security

SEO Analysis

C67/100

costco.comcostco.com

Welcome to Costco Wholesale

Shop Costco.com for electronics, computers, furniture, outdoor living, appliances, jewelry and more. Enjoy low warehouse prices on name-brands products deliv...

Description truncated.

Title Length27 chars

Recommended: 50-60 chars

Description Length174 chars

Recommended: 120-160 chars

Issues (0)

5 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

10 URLs

robots.txt

57 rules

Sitemap reference found

Sponsored

Security Score

61%Fair

Interactive

HTTPS

WAF

205d

Certificate Details

Type

Extended Validation (EV)

Certificate Authority

DigiCert Inc

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

Valid From

04.09.2025

Valid Until

06.09.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

costco.comwww.costco.com

SHA-256 Fingerprint

4B:FF:F7:23:E5:C7:C3:8A:3A:9E:A8:66:5D:BB:47:3A:C5:9B:86:D9...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

content-security-policy

default-src 'self' https://*.queue-it.net/ https://*.costco....

x-build-reference

1.20.16-21925999282

x-build-tag

prd-usbc-release-v1.20.16

x-next-i18n-router-locale

en-us

x-middleware-rewrite

/en-us

x-nextjs-cache

HIT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

100

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (2)

mx0a-001f9d01.pphosted.com

mx0b-001f9d01.pphosted.com

Domain Information

costco.com

Domain Age

28y 11m

Created

17.03.1997

Expires

18.03.2026

Last Updated

14.03.2025

Registrar

CSC Corporate Domains, Inc.

DNSSEC

Not Enabled

Privacy & Compliance

OneTrust

Cookie Consent Banner

OneTrust

GDPR Indicators

Cookie consent banner detected

CMP: OneTrust

Data Protection Officer mentioned

Typography & Readability

Helvetica Neue

66/100

Readability

/30

20/40

13px · LH 1.50

Hierarchy

/20

25/25

2.46x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Helvetica Neue

Sans32px

Body Font

Helvetica Neue

Sans13px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

32px

24px

14px

13px

❌ Critical: 13px body text is too small. Increase to at least 14px.

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 2.5x 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.

Buy on MyFonts

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

24 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(20)

Website Identity

costco.com

28 years old

CSC Corporate Domains, Inc.

Social Profiles

Facebook Instagram Pinterest

Sponsored

Last analyzed: 13 Feb 2026 at 00:15

Historical Analysis & Change Tracking