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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protonmail.com

https://protonmail.com· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

protonmail.com

Sponsored

Hosting Provider

Protonmail Mnt

IP Address

185.70.42.12

Server Location

🇩🇪 Frankfurt am Main, Germany

ASN

AS62371

Organization

Protonmail Mnt

Nameservers

ns3.protonmail.com.ns2.protonmail.com.ns1.protonmail.com.

Performance

Page Speed

499 KB

162 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Hybrid

⚙️ SSR

Frontend

Framework

Astro

Styling

Tailwind CSS

Infrastructure

Hosting

Protonmail Mnt

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

2 Technologies Detected

Meta Frameworks

Astro

CSS Frameworks

Tailwind CSS

SEO Analysis

C67/100

protonmail.comprotonmail.com

Proton Mail: Get a free email account with privacy and encryption |...

Proton Mail is the world’s largest secure email service with over 100 million users. Available on Web, iOS, Android, and desktop. Protected by Swiss privacy ...

Title truncated. Description truncated.

Title Length83 chars

Recommended: 50-60 chars

Description Length161 chars

Recommended: 120-160 chars

Issues (0)

6 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

23 URLs

robots.txt

6 rules

Sitemap reference found

Sponsored

Security Score

71%Good

Interactive

HTTPS

No WAF

66d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (4096 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

25.01.2026

Valid Until

25.04.2026

Subject Alternative Names (5)

*.pr.tn*.proton.me*.storage.proton.mepr.tnproton.me

SHA-256 Fingerprint

7C:A1:E5:55:03:45:18:EB:46:21:EF:E4:D8:22:18:63:5C:AC:05:30...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

cache-control

🔴 No Cache(no-store, no-cache, must-revalidate, proxy-revalidate)

content-encoding

📦 Gzip(gzip)

content-length

29463

content-security-policy

default-src 'self'; media-src https://static.zdassets.com ht...

content-type

text/html; charset=utf-8

Good Warning Issue

Email Infrastructure

Proton Mail

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (2)

mail.protonmail.ch

mailsec.protonmail.ch

Domain Information

protonmail.com

Domain Age

15y 6m

Created

21.08.2010

Expires

21.08.2026

Last Updated

20.07.2024

Registrar

MarkMonitor Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Typography & Readability

Arizona + Inter

71/100

Readability

/30

32/40

16px · LH 1.57

Hierarchy

/20

18/25

3.43x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Arizona

Sans54px

Body Font

Inter

Sans16px

Contrast Ratio

Reading Comfort

~37 CPL

Needs attention

54px

27px

16px

⚠️ Small text: 16px may be hard to read on mobile. Consider 16px+.

✅ Optimal line spacing: 1.57 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 3.4x 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.

✅ Protected text on images: Using gradient for readability.

Buy on MyFonts

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

2 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(1)

Website Identity

Facebook X (Twitter)Instagram LinkedIn TikTok Discord Telegram Reddit Threads Bluesky

Sponsored

Last analyzed: 17 Feb 2026 at 22:48

Historical Analysis & Change Tracking