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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pragprog.com

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

Export

pragprog.com

Sponsored

Hosting Provider

DigitalOcean

digitalocean.com

IP Address

64.23.242.214

Server Location

🇺🇸 Santa Clara, United States

ASN

AS14061

Organization

DigitalOcean, LLC

Server

we-prefer-the-term-willing-assistant

Nameservers

ns-275.awsdns-34.com.ns-960.awsdns-56.net.ns-1266.awsdns-30.org.ns-1538.awsdns-00.co.uk.

Performance

Page Speed

317 KB

32 requests

Image Optimization

Responsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

DigitalOcean

Technology Stack

7 Technologies Detected

Analytics

Libraries

CSS Frameworks

Icon Libraries

Fonts

Tag Managers

SEO Analysis

D58/100

pragprog.compragprog.com

Pragmatic Bookshelf: By Developers, For Developers

We improve the lives of professional developers. We create timely, practical books on classic and cutting-edge topics to help you learn and practice your cra...

Description truncated.

Title Length50 chars

Recommended: 50-60 chars

Description Length208 chars

Recommended: 120-160 chars

Issues (0)

6 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

1,681 URLs

robots.txt

Sponsored

Security Score

21%Critical

Interactive

HTTPS

No WAF

53d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/1.1

Valid From

13.01.2026

Valid Until

13.04.2026

Subject Alternative Names (5)

*.pragmatic.org*.pragmaticprogrammer.com*.pragprog.compragmaticprogrammer.compragprog.com

SHA-256 Fingerprint

97:68:98:DF:2E:E5:B4:B7:E0:46:70:29:5B:89:79:31:7A:5B:36:A2...

Top Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

connection

keep-alive

content-length

31270

content-type

text/html; charset=utf-8

date

Thu, 19 Feb 2026 12:19:01 GMT

etag

"69797c3f-7a26"

Good Warning Issue

Email Infrastructure

Rackspace Email

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (2)

mx2.emailsrvr.com

mx1.emailsrvr.com

Domain Information

pragprog.com

Domain Age

27y 1m

Created

19.01.1999

Expires

19.01.2027

Last Updated

14.01.2026

Registrar

1API GmbH

DNSSEC

Not Enabled

Privacy & Compliance

Cookiebot

Cookie Consent Banner

Cookiebot

GDPR Indicators

Cookie consent banner detected

CMP: Cookiebot

Typography & Readability

noto sans

70/100

Readability

/30

32/40

16px · LH 1.34

Hierarchy

/20

15/25

1.1x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

noto sans

Sans18px

Body Font

noto sans

Sans16px

Contrast Ratio

Reading Comfort

~37 CPL

Needs attention

18px

16px

18px

16px

Minor Second

Scale

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

⚠️ Weak hierarchy: Headlines should be at least 2x body size for clear visual structure.

✅ 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.

⚠️ Inconsistent alignment: Mix of left/center/right creates visual noise.

GGoogle Fonts

Business & Marketing Stack

3 Tools Detected

Growing

Behavior Analytics

Google Tag ManagerFree

PostHogMid-Market

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

14 Resources

Scripts

Styles

Async

Defer

Top Script Sources

us-assets.i.posthog.com(4)pragprog.com(2)googletagmanager.com(1)transactions.sendowl.com(1)cdn.jsdelivr.net(1)

Website Identity

Facebook X (Twitter)Instagram LinkedIn Bluesky

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Last analyzed: 19 Feb 2026 at 12:19

Historical Analysis & Change Tracking