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

21cn.com

https://21cn.com· First analyzed 19 Feb 2026· Updated 19 Feb 2026

Export

21cn.com

Sponsored

Hosting Provider

Chinanet JS

IP Address

114.217.37.13

Server Location

🇨🇳 Suzhou, China

ASN

AS4134

Organization

Chinanet JS

Server

Nginx

Nameservers

vip4.alidns.com.vip3.alidns.com.

Performance

Page Speed

2 requests

0–49

50–89

90–100

Architecture Stack

Headless

⚙️ SSR

Decoupled

API

Data Source

Headless CMS

Strapi

Infrastructure

Hosting

Chinanet JS

Detected API Sources

https://ux.21cn.com/api/htmlRe...

Technology Stack

6 Technologies Detected

Other

GSAP AOS (Animate On Scroll)ScrollMagic

Libraries

jQuery

CSS Frameworks

Tailwind CSS

Web Servers

Nginx

SEO Analysis

F38/100

21cn.com21cn.com

首页 | 天翼数字生活科技有限公司

No description available for this page.

Title Length17 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (2)

• Missing meta description - important for click-through rates
• Missing H1 tag - every page should have one H1

7 issues found

Upgrade to view details

Sponsored

Security Score

21%Critical

Interactive

HTTPS

No WAF

72d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

WoTrus CA Limited

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/1.1

Valid From

01.04.2025

Valid Until

02.05.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.dlife.cndlife.cn

SHA-256 Fingerprint

73:22:60:8B:75:D1:3A:B3:8A:4E:B4:DF:30:8D:38:B4:43:89:D0:B5...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

connection

keep-alive

content-length

239657

content-type

text/html; charset=utf-8

date

Thu, 19 Feb 2026 10:25:19 GMT

server

nginx

set-cookie

F82089F504F67EE2

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

MX Records (1)

mta.21cn.com

Domain Information

21cn.com

Domain Age

27 years

Created

08.02.1999

Expires

08.02.2027

Last Updated

16.05.2025

Registrar

Xiamen 35.com Information Co., Ltd.

DNSSEC

Not Enabled

Typography & Readability

-apple-system

73/100

Readability

/30

40/40

20px · LH 1.50

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

-apple-system

Sans

Body Font

-apple-system

Sans20px

Contrast Ratio

Reading Comfort

~69 CPL

Optimal (45–75)

20px

Minor Second

Scale

✅ Excellent readability: 20px body text is ideal for all devices.

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Excellent performance: System fonts eliminate font loading delays (better LCP).

✅ Consistent design: Single font family with weight variations is a modern best practice.

✅ Protected text on images: Using gradient for readability.

✅ Optimal line length: ~68 characters per line is comfortable to read.

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

22 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(10)dlife.cn(7)ux.21cn.com(2)

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Last analyzed: 19 Feb 2026 at 10:25

Historical Analysis & Change Tracking