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

ens.fr

https://ens.fr· First analyzed 14 Feb 2026· Updated 14 Feb 2026

Export

ens.fr

Mobile

Sponsored

Hosting Provider

Super.so

super.so

IP Address

129.199.166.211

Server Location

🇫🇷 Paris, France

ASN

AS2200

Server

Apache

Nameservers

ns2.ens.fr.ns1.ens.fr.ext.lri.fr.ns2.nic.fr.+1 more

Performance

Page Speed

2 MB

138 requests

Image Optimization

Lazy Load

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Drupal

Technology Stack

13 Technologies Detected

Libraries

CSS Frameworks

Analytics

Meta Frameworks

Other

AOS (Animate On Scroll)

Icon Libraries

Font Awesome

Fonts

Google Fonts

Web Servers

Apachev2.4.66

SEO Analysis

D47/100

ens.frens.fr

Accueil | ENS

L’ENS est un établissement public à caractère scientifique, culturel et professionnel (EPSCP) au sens de l’article L. 716-1 du code de l’éducation placé sous...

Description truncated.

Title Length13 chars

Recommended: 50-60 chars

Description Length947 chars

Recommended: 120-160 chars

Issues (1)

• Missing H1 tag - every page should have one H1

7 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

3,161 URLs

robots.txt

53 rules

Sponsored

Security Score

56%Poor

Interactive

HTTPS

No WAF

237d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

Hellenic Academic and Research Institutions CA

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

09.10.2025

Valid Until

09.10.2026

OCSP Stapling

Enabled

Subject Alternative Names (4)

ens.psl.euwww.ens.psl.euens.frwww.ens.fr

SHA-256 Fingerprint

25:AC:37:73:24:16:D8:46:B3:36:C8:99:80:D6:A4:91:D7:8B:D6:45...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

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HTTP Headers

Developer Console

cache-control

🟡 1 Hours(max-age=3600, public)

content-encoding

📦 Gzip(gzip)

content-language

content-type

text/html; charset=UTF-8

date

Sat, 14 Feb 2026 12:37:47 GMT

etag

"1770997378-gzip"

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (2)

mx1.relay.renater.fr

mx2.relay.renater.fr

Domain Information

ens.fr

Domain Age

31y 1m

Created

31.12.1994

Expires

31.12.2026

Last Updated

31.01.2026

Registrar

GIP RENATER

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Typography & Readability

Crimson Text + Times New Roman

34/100

Readability

/30

25/40

16px · LH 1.15

Hierarchy

/20

8/25

WCAG

/25

5/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Crimson Text

Serif

Body Font

Times New Roman

Serif16px

Contrast Ratio

Reading Comfort

~54 CPL

Optimal (45–75)

36px

44px

16px

Minor Second

Scale

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

⚠️ Tight line spacing (1.15). Consider 1.4-1.6 for better readability.

✅ Good performance: Using 2 font families keeps load times fast.

⚠️ Risky: Text appears on background images without overlay protection.

✅ Optimal line length: ~54 characters per line is comfortable to read.

⚠️ Cramped layout: 19 elements lack adequate spacing.

Buy on MyFonts

Business & Marketing Stack

4 Tools Detected

Advanced

Behavior Analytics

HotjarMid-Market

Matomo (Piwik)Mid-Market

Google AnalyticsFree

User behavior and product analytics

Social Media

Twitter/X WidgetsFree

Social widgets and sharing tools

Sponsored

Scripts & Styles

30 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(15)platform.twitter.com(2)stats-web.ens.psl.eu(1)static.hotjar.com(1)cdn.jsdelivr.net(1)

Website Identity

Facebook X (Twitter)Instagram

Sponsored

Last analyzed: 14 Feb 2026 at 12:37

Historical Analysis & Change Tracking