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

tailwindcss.com

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

Export

tailwindcss.com

Mobile

Sponsored

Hosting Provider

Cloudflare

cloudflare.com

IP Address

172.67.68.11

Server Location

🇨🇦 Toronto, Canada

ASN

AS13335

Organization

Cloudflare, Inc.

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

anuj.ns.cloudflare.com.roxy.ns.cloudflare.com.

Performance

Page Speed

7.4 MB

91 requests

Image Optimization

Lazy LoadResponsiveImageKitVercel Image Optimization

0–49

50–89

90–100

Architecture Stack

Hybrid

🔀 Hybrid

Frontend

Framework

Next.js

Styling

Tailwind CSS

CMS

Webflow

Infrastructure

Hosting

Cloudflare

CDN

Cloudflare

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

5 Technologies Detected

Meta Frameworks

CSS Frameworks

Icon Libraries

Analytics

CDN

SEO Analysis

D58/100

tailwindcss.comtailwindcss.com

Tailwind CSS - Rapidly build modern websites without ever leaving y...

Tailwind CSS is a utility-first CSS framework for rapidly building modern websites without ever leaving your HTML.

Title truncated.

Title Length76 chars

Recommended: 50-60 chars

Description Length114 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (28/43)

5 issues found

Upgrade to view details

Sponsored

Security Score

41%Poor

Interactive

HTTPS

WAF

66d

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

21.01.2026

Valid Until

21.04.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

tailwindcss.com*.tailwindcss.com

SHA-256 Fingerprint

61:49:94:E8:FB:D1:24:14:DF:C9:92:BE:60:84:A8:D8:37:E3:89:DC...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

age

cache-control

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

cf-cache-status

DYNAMIC

cf-ray🇩🇪 Frankfurt

9cd76b6a6e5fdc60-FRA

content-encoding

⚡ Brotli(br)

content-type

text/html; charset=utf-8

Good Warning Issue

Email Infrastructure

Fastmail

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (2)

in1-smtp.messagingengine.com

in2-smtp.messagingengine.com

Domain Information

tailwindcss.com

Domain Age

8y 7m

Created

20.07.2017

Expires

20.07.2032

Last Updated

05.01.2023

Registrar

Tucows Domains Inc.

DNSSEC

Not Enabled

Typography & Readability

inter

81/100

Readability

/30

40/40

18px · LH 1.56

Hierarchy

/20

18/25

5.33x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

inter

Sans96px

Body Font

inter

Sans18px

Contrast Ratio

Reading Comfort

~41 CPL

Needs attention

96px

40px

16px

18px

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

✅ Optimal line spacing: 1.56 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 5.3x 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

2 Tools Detected

Growing

Behavior Analytics

FathomSMB

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

22 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(19)cdn.usefathom.com(1)

Website Identity

X (Twitter)GitHub

Sponsored

Last analyzed: 13 Feb 2026 at 21:29

Historical Analysis & Change Tracking