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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v0.app

https://v0.app· First analyzed 26 Apr 2026· Updated 26 Apr 2026

Export

v0.app

Mobile

Sponsored

Hosting Provider

Vercel

vercel.com

IP Address

64.239.109.65

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 Walnut, United States

ASN

AS16509

Organization

Vercel, Inc

Server

Vercel

Nameservers

ns2.vercel-dns.com.ns1.vercel-dns.com.

Performance

Core Web Vitals

Weight

First Contentful Paint

1.0 s10%

Speed Index

1.4 s10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

5.9 MB

205 requests

Image Optimization

Lazy LoadResponsiveVercel Image Optimization

0–49

50–89

90–100

Architecture Stack

Hybrid

🔀 Hybrid

Frontend

Framework

Next.js

Styling

Tailwind CSS

Infrastructure

Platform

Vercel

CDN

Vercel Image

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

4 Technologies Detected

Meta Frameworks

Other

CSS Frameworks

Platforms

SEO Analysis

B71/100

Meta Tags13/15

Content8/12

Headings8/8

Technical18/21

E-E-A-T2/7

Images4/7

Links5/5

URL5/5

Social4/5

Freshness0/4

Mobile1/4

Indexability3/3

v0.appv0.app

v0 by Vercel - Build Agents, Apps, and Websites with AI

Your collaborative AI assistant to design, iterate, and scale full-stack applications for the web.

Title Length55 chars

Recommended: 50-60 chars (~329px / 580px)

Description Length98 chars

Recommended: 120-160 chars

Issues (1)

• Most images missing alt text (123/187) — critical for accessibility and SEO

7 issues found

Upgrade to view details

Local SEO

Local Search Readiness

15/100

Poor

4 13

This site doesn't appear to be a local business. Local SEO signals are optional for non-local websites.

Sponsored

AI & LLM Readiness

D48/100

Bot Access

20/25

Machine Read.

13/25

Schema Data

3/25

Citation

12/25

AI Bot Access

14/14 accessible

AI Search

OAI-SearchBot

PerplexityBot

Claude-SearchBot

Gemini-Deep-Research

DuckAssistBot

Training

GPTBot

ClaudeBot

Google-Extended

Meta-ExternalAgent

Bytespiderinfo

Amazonbot

Applebot-Extended

CCBotinfo

Fetch

ChatGPT-User

Machine Readability

llms.txt

llms-full.txt

Semantic HTML

Heading Hierarchy

nav

Text ratio:1%

Words:867

Token eff.:Optimal

Depth:1/5

Structured Data

2 JSON-LD

Organization×1.1

sameAs entity links

Citation Readiness

Opening Summary19w

Descriptive Headingsavg 4w

Canonical URL

Open Graph3/3

Twitter Card3/3

Language Tag

Publish Date

Author Info

Lists

Tables

TL;DR / Summary

About Page Link

Recommendations (8)

AI readiness recommendation preview...

Upgrade to view recommendations

Sponsored

Accessibility

WCAG 2.1 Compliance

Evaluates how accessible your website is for users with disabilities, based on WCAG 2.1 guidelines. Checks images, forms, keyboard navigation, ARIA roles, and color contrast.

86/100

Passed

Critical

Warnings

Images & Alt Text

20/20

Checks if images have descriptive alt text for screen readers and visually impaired users.

Semantic Structure

20/20

Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.

Forms & Inputs

15/15

Verifies form fields have labels, error messages are clear, and inputs are properly associated.

Color & Contrast

15/15

Tests text-to-background color contrast ratios against WCAG AA/AAA minimum requirements.

Keyboard & Focus

11/15

Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).

ARIA & Roles

5/15

Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.

2 recommendations

•Accessibility recommendation preview...

Upgrade to view recommendations

Carbon Footprint

SWDM v4 · Eco-Score

Carbon emissions estimated using the Sustainable Web Design Model v4 (SWDM v4). Factors in data center, network, and device energy across new and returning visitors. Grade thresholds based on HTTP Archive percentiles.

45/100

615 mg

CO₂e / view

5.9 MB

Page Weight

Cleaner Than

New Visitor

703 mg

Returning (cached)

351 mg

Annual (10K/mo)

73.8 kg

Emission Segments

Data Center

30 mg

Network

181 mg

Device

404 mg

Resource Breakdown

JavaScript

2.2 MB

Images

2.7 MB

CSS

97.3 KB

Fonts

149.9 KB

HTML

73.6 KB

Other

735.2 KB

Green Hosting Verified

Vercel

Provider Match

7 recommendations

•Carbon footprint recommendation preview...

Upgrade to view recommendations

Security Score

61%Fair

Interactive

HTTPS

No WAF

54d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

22.03.2026

Valid Until

20.06.2026

Subject Alternative Names (2)

*.v0.appv0.app

SHA-256 Fingerprint

FB:0B:AA:DC:21:2E:40:57:DB:FE:01:8A:9C:1F:B1:7E:6E:97:FD:4D...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

access-control-allow-origin

age

100362

cache-control

🟡 0s(public, max-age=0, must-revalidate)

content-disposition

inline

content-encoding

⚡ Brotli(br)

content-security-policy

default-src 'self'; img-src 'self' blob: data: https://verce...

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

Domain Information

v0.app

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Data Protection Officer mentioned

Mobile Compatibility

Viewport & Responsive Test

Tests how well your website works on mobile devices. Checks viewport configuration, responsive layout, touch targets, font readability, and simulates rendering across different screen sizes.

80/100

Mobile Friendly7 breakpoints

Viewport Meta

The viewport meta tag tells mobile browsers how to scale the page. Without it, mobile devices render at desktop width.

Responsive Design

Uses CSS media queries or flexible layouts to adapt content to different screen sizes automatically.

Touch Icons

Apple touch icons and favicons displayed when users add the site to their home screen on mobile devices.

Readable Font Size

Base font size should be at least 16px on mobile to ensure text is readable without zooming.

Relative Units

Using em, rem, %, or vw instead of fixed px values allows content to scale properly across screen sizes.

No H-Scroll Risk

No elements wider than the viewport that would cause horizontal scrolling on mobile devices.

Tap Targets OK

Interactive elements (buttons, links) are at least 48x48px with enough spacing to prevent accidental taps.

No Fixed Widths

No elements with fixed pixel widths that could overflow on smaller screens and break the layout.

Viewport

width=device-width, initial-scale=1, maximum-scale=1

2 recommendations

•Mobile compatibility recommendation preview...

Upgrade to view recommendations

Typography & Readability

GeistSans

82/100

Readability

/30

25/30

16px · LH 1.50

Hierarchy

/20

19/20

2x ratio · ✓ H1→H6

WCAG

/25

18/25

Performance

/25

20/25

1 font · 3 req

Heading Font

GeistSans

Sans32px

Body Font

GeistSans

Sans16px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

32px

48px

16px

Major Third

Scale

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

✅ Optimal line spacing: 1.50 ratio (ideal range 1.4–1.6).

✅ Perfect heading hierarchy: Sequential h1→h2→h3 with single H1 — ideal for SEO & accessibility.

✅ Strong hierarchy: Headlines are 2.0x larger than body text.

✅ Lean font stack: 1 font families keeps load times fast.

✅ Smart font loading: font-display: swap prevents invisible text during load (FOIT).

Buy on MyFontsFlesch 60

Color Palette

5 unique colors

19.8:1 AAA Light

#ffffff

Background· 84.5%

#0a0a0a

Text· 9.600000000000001%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

26 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(20)

Website Identity

Vercel

Organization

Your collaborative AI assistant to design, iterate, and scale full-stack applications for the web.

vercel.com

Location detected: 🇺🇸 United Statesvia ip

Social Profiles

X (Twitter)LinkedIn

Sponsored

Last analyzed: 26 Apr 2026 at 17:05

Historical Analysis & Change Tracking