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.

Technology Comparison

U Paris13 vs Nginx

Side-by-side comparison based on real-world adoption data from 3,195 detections across analyzed websites.

Market Share Distribution

U Paris13 (0%)Nginx (100%)

Total Detections

U Paris13

3,194

Nginx

HIGHER

Websites Using

U Paris13

3,192

Nginx

HIGHER

Used Together

websites use both

U Paris13

Hosting

1 detections

1 sites

View Profile

Nginx

Hosting

Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.

3,194 detections

3192 sites

Visit Website View Profile

Our Analysis

Nginx is significantly more popular than U Paris13 in our dataset, appearing on 3192 websites compared to 1. Both are in the Hosting category, making them direct alternatives.

Sites Using Both (0)

No sites use both technologies together.

Only U Paris13

univ-paris13.fr

Only Nginx

007.com 1-x.bet 1001fonts.com 1101.com 123formbuilder.com 123pan.com 126.com 126.net 17173.com 1gb.ru

Frequently Asked Questions

What is the difference between U Paris13 and Nginx?

U Paris13 is a hosting technology. Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache. Both belong to the Hosting category, making them direct alternatives.

Which is more popular, U Paris13 or Nginx?

Based on our analysis of real websites, Nginx is more widely adopted with 3,194 detections compared to U Paris13's 1.

Can U Paris13 and Nginx be used together?

In our current dataset, no websites use both technologies simultaneously. This suggests they typically serve as alternatives rather than complementary tools.

Check Any Website's Technology Stack

Find out if a website uses U Paris13, Nginx, or any other technology.

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