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

39.net

https://39.net· First analyzed 15 Feb 2026· Updated 15 Feb 2026

Export

39.net

Mobile

Sponsored

Hosting Provider

Chinanet

IP Address

115.231.220.253

Server Location

🇨🇳 Shaoxing, China

ASN

AS58461

Server

OpenResty

Performance

Page Speed

8 KB

99 requests

Image Optimization

Lazy Load

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Chinanet

Technology Stack

2 Technologies Detected

Libraries

jQueryv1.8.3

Web Servers

OpenResty

SEO Analysis

F23/100

39.net39.net

39健康网_优质医疗保健信息与在线健康服务平台

No description available for this page.

Title Length23 chars

Recommended: 50-60 chars

Description Length0 chars

Recommended: 120-160 chars

Issues (4)

• Missing meta description - important for click-through rates
• Missing H1 tag - every page should have one H1
• Many images missing alt text (90/90)

8 issues found

Upgrade to view details

Crawlability

Sitemap

robots.txt

4 rules

Allows all crawlers

Sponsored

Security Score

46%Poor

Interactive

HTTPS

No WAF

61d

Certificate Details

Type

Domain Validated (DV)

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

17.04.2025

Valid Until

17.04.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.39.net39.net

SHA-256 Fingerprint

9C:01:5F:97:B4:C2:AC:15:A3:1E:7E:9B:B0:A5:62:DE:0F:CC:84:78...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ranges

bytes

age

cache-control

🔵 Public(public)

connection

keep-alive

content-encoding

📦 Gzip(gzip)

content-length

18632

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

Domain Information

39.net

Domain Age

29y 1m

Created

21.01.1997

Expires

22.01.2029

Last Updated

04.01.2026

Registrar

Alibaba Cloud Computing (Beijing) Co., Ltd.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

Typography & Readability

Microsoft Yahei

29/100

Readability

/30

25/40

22px · LH 1.00

Hierarchy

/20

8/25

WCAG

/25

5/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Microsoft Yahei

Body Font

Microsoft Yahei

Sans22px

Contrast Ratio

Reading Comfort

~94 CPL

Needs attention

22px

✅ Excellent readability: 22px body text is ideal for all devices.

⚠️ Tight line spacing (1.00). Consider 1.4-1.6 for better readability.

✅ Good performance: Using 1 font families keeps load times fast.

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

⚠️ Wide lines: ~94 chars/line. Consider max-width for better reading flow.

⚠️ Cramped layout: 46 elements lack adequate spacing.

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Scripts & Styles

22 Resources

Scripts

Styles

Async

Defer

Top Script Sources

static.39.net(13)hm.baidu.com(2)classic.39health.com(2)pos.baidu.com(1)hmcdn.baidu.com(1)

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Last analyzed: 15 Feb 2026 at 07:24

Historical Analysis & Change Tracking