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

nxtbook.com

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

Export

nxtbook.com

Sponsored

Hosting Provider

Amazon Web Services (AWS)

aws.amazon.com

IP Address

3.213.53.25

Server Location

🇺🇸 Ashburn, United States

ASN

AS14618

Organization

AWS EC2 (us-east-1)

Server

Flywheel/5.1.0

CDN

Fastly

Nameservers

ns41.constellix.net.ns51.constellix.net.ns61.constellix.net.ns11.constellix.com.+2 more

Performance

Page Speed

778 KB

87 requests

Image Optimization

Lazy LoadWebPResponsive

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

WordPressv6.9.1

cms

nxtbook_mediaCustom

Technology Stack

14 Technologies Detected

Analytics

Google Analytics

Google Analytics 4

Microsoft Clarity

Plugins

Activecampaign Subscription Forms

Libraries

Advertising

LinkedIn Ads Microsoft Advertising

Other

AOS (Animate On Scroll)

CSS Frameworks

Tailwind CSS

Tag Managers

Google Tag Manager

Platforms

Fly.io

SEO Analysis

A82/100

nxtbook.comnxtbook.com

Digital Content Experience Platform | Nxtbook

Create engaging content for your brand or business using our responsive digital publishing platform. From eBooks to magazines and more. Schedule a Demo!

Title Length45 chars

Recommended: 50-60 chars

Description Length152 chars

Recommended: 120-160 chars

Issues (0)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

robots.txt

3 rules

Sitemap reference found

Allows all crawlers

Sponsored

Security Score

36%Critical

Interactive

HTTPS

No WAF

79d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

06.02.2026

Valid Until

07.05.2026

Subject Alternative Names (4)

nxtbookmedia.comnxtcreative.comwww.nxtbookmedia.comwww.nxtcreative.com

SHA-256 Fingerprint

0F:74:75:09:A3:4B:E8:E7:2C:61:97:DF:6B:39:C2:D8:C4:28:7F:7A...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

content-encoding

📦 Gzip(gzip)

content-length

19699

content-type

text/html; charset=UTF-8

date

Tue, 17 Feb 2026 13:16:52 GMT

fastly-restarts

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (5)

aspmx2.googlemail.com

aspmx.l.google.com

alt1.aspmx.l.google.com

aspmx3.googlemail.com

+1 more

Domain Information

nxtbook.com

Domain Age

22y 8m

Created

19.06.2003

Expires

19.06.2026

Last Updated

17.06.2025

Registrar

Name.com, Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Typography & Readability

Helvetica Neue

59/100

Readability

/30

20/40

14px · LH 1.50

Hierarchy

/20

25/25

4.12x ratio

WCAG

/25

11/15

Contrast: undefined

Performance

/25

10/20

4 fonts

Heading Font

Helvetica Neue

Sans56px

Body Font

Helvetica Neue

Sans14px

Contrast Ratio

Reading Comfort

~58 CPL

Optimal (45–75)

56px

32px

31px

28px

14px

❌ Critical: 14px body text is too small. Increase to at least 14px.

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 4.1x larger than body text.

✅ 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.

✅ Protected text on images: Using gradient for readability.

Buy on MyFonts

Business & Marketing Stack

6 Tools Detected

Enterprise

Marketing Automation

ActiveCampaignMid-Market

Email marketing and automation platforms

Behavior Analytics

Microsoft ClarityFree

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Advertising

LinkedIn AdsEnterprise

Microsoft AdsEnterprise

Ad platforms and retargeting pixels

Sponsored

Scripts & Styles

23 Resources

Scripts

Styles

Async

Defer

Top Script Sources

googletagmanager.com(4)bat.bing.com(3)clarity.ms(2)diffuser-cdn.app-us1.com(2)nxtbookmedia.com(2)

Website Identity

Facebook X (Twitter)Instagram

Sponsored

Last analyzed: 17 Feb 2026 at 13:17

Historical Analysis & Change Tracking