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

html5rocks.com

https://html5rocks.com· First analyzed 19 Feb 2026· Updated 19 Feb 2026

Export

html5rocks.com

Sponsored

Hosting Provider

Google Cloud Platform

cloud.google.com

IP Address

216.58.210.147

Server Location

🇺🇸 Mountain View, United States

ASN

AS15169

Organization

Google LLC

Server

Google Frontend

Nameservers

ns3.google.com.ns2.google.com.ns1.google.com.ns4.google.com.

Performance

Page Speed

133 KB

62 requests

Image Optimization

Lazy LoadResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Google Cloud Platform

Progressive Web App

Web ManifestApple Touch IconTheme Color

Technology Stack

8 Technologies Detected

Analytics

Frameworks

CSS Frameworks

Icon Libraries

Fonts

Tag Managers

Languages

SEO Analysis

C61/100

html5rocks.comhtml5rocks.com

web.dev

Guidance to build modern web experiences that work on any browser.

Title Length7 chars

Recommended: 50-60 chars

Description Length66 chars

Recommended: 120-160 chars

Issues (2)

• Missing H1 tag - every page should have one H1
• Many images missing alt text (8/10)

4 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

robots.txt

3 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

66%Fair

Interactive

HTTPS

No WAF

59d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Google Trust Services

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

26.01.2026

Valid Until

20.04.2026

OCSP Stapling

Enabled

Subject Alternative Names (20)

devsite-sni.developers.google.comdocs.actifio.comd.actifio.comapigee.com*.apigee.comappdefensealliance.dev*.appdefensealliance.devbazel.build+12 more

SHA-256 Fingerprint

8C:A2:84:E0:EB:D9:45:37:01:3C:45:C3:59:15:86:B2:D1:5B:C3:A6...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

alt-svc

h3=":443"; ma=2592000,h3-29=":443"; ma=2592000

cache-control

🔴 No Cache(no-cache, must-revalidate)

content-encoding

📦 Gzip(gzip)

content-length

21593

content-security-policy

base-uri 'self'; object-src 'none'; script-src 'strict-dynam...

content-type

text/html; charset=utf-8

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

Domain Information

html5rocks.com

Domain Age

16y 1m

Created

18.01.2010

Expires

18.01.2027

Last Updated

17.12.2025

Registrar

MarkMonitor Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Data Protection Officer mentioned

Typography & Readability

Noto Sans

51/100

Readability

/30

40/40

16px · LH 1.50

Hierarchy

/20

8/25

WCAG

/25

5/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Noto Sans

Sans

Body Font

Noto Sans

Sans16px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

48px

64px

Perfect Fourth

Scale

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

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ 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.

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

GGoogle Fonts

Business & Marketing Stack

2 Tools Detected

Growing

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

25 Resources

Scripts

Styles

Async

Defer

Top Script Sources

gstatic.com(16)googletagmanager.com(4)

Website Identity

X (Twitter)YouTube

Sponsored

Last analyzed: 19 Feb 2026 at 17:06

Historical Analysis & Change Tracking