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

codesandbox.io

https://codesandbox.io· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

codesandbox.io

Mobile

Sponsored

Hosting Provider

Cloudflare

cloudflare.com

IP Address

172.64.144.247

Server Location

🇨🇦 Toronto, Canada

ASN

AS13335

Organization

Cloudflare, Inc.

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

adel.ns.cloudflare.com.greg.ns.cloudflare.com.

Performance

Page Speed

4.6 MB

55 requests

Image Optimization

Lazy LoadResponsiveVercel Image Optimization

0–49

50–89

90–100

Architecture Stack

Hybrid

🔀 Hybrid

Frontend

Framework

Next.js

Infrastructure

Hosting

Cloudflare

CDN

Cloudflare

Technology Stack

4 Technologies Detected

Meta Frameworks

Next.js Astro

CSS Frameworks

Tailwind CSS

CDN

Cloudflare

SEO Analysis

A82/100

codesandbox.iocodesandbox.io

CodeSandbox: Instant Cloud Development Environments

CodeSandbox is a cloud development platform that empowers developers to code, collaborate and ship projects of any size from any device in record time.

Title Length51 chars

Recommended: 50-60 chars

Description Length151 chars

Recommended: 120-160 chars

Issues (0)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

robots.txt

2 rules

Allows all crawlers

Sponsored

Security Score

26%Critical

Interactive

HTTPS

WAF

75d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

02.02.2026

Valid Until

03.05.2026

Subject Alternative Names (2)

*.nodebox.codesandbox.iocodesandbox.io

SHA-256 Fingerprint

90:0C:8A:93:15:C8:AC:E3:BF:15:D5:12:67:A7:CC:10:C1:19:E6:DD...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

date

Tue, 17 Feb 2026 13:47:37 GMT

content-type

text/html; charset=utf-8

content-encoding

⚡ Brotli(br)

vary

RSC, Next-Router-State-Tree, Next-Router-Prefetch, Next-Url,...

x-nextjs-cache

HIT

x-powered-by

Next.js

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (5)

alt1.aspmx.l.google.com

aspmx.l.google.com

alt2.aspmx.l.google.com

alt3.aspmx.l.google.com

+1 more

Domain Information

codesandbox.io

Domain Age

9y 2m

Created

23.11.2016

Expires

23.11.2029

Last Updated

26.10.2020

Registrar

NameCheap, Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookiebot

Cookie Consent Banner

Cookiebot

GDPR Indicators

Cookie consent banner detected

CMP: Cookiebot

Typography & Readability

Inter + __Inter_f367f3

82/100

Readability

/30

40/40

18px · LH 1.40

Hierarchy

/20

21/25

6.67x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Inter

Sans120px

Body Font

__Inter_f367f3

Sans18px

Contrast Ratio

Reading Comfort

~42 CPL

Needs attention

120px

24px

14px

24px

18px

✅ Excellent readability: 18px body text is ideal for all devices.

✅ Optimal line spacing: 1.40 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 6.7x 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: 57 elements lack adequate spacing.

Buy on MyFontsVariable Fonts

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

23 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(20)

Website Identity

codesandbox.io

9 years old

NameCheap, Inc.📧 Google Workspace

Social Profiles

X (Twitter)YouTube GitHub

Sponsored

Last analyzed: 17 Feb 2026 at 13:48

Historical Analysis & Change Tracking