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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51job.com

https://51job.com· First analyzed 13 Feb 2026· Updated 13 Feb 2026

Export

51job.com

Mobile

Sponsored

Hosting Provider

Chinanet SH

IP Address

114.80.176.40

Server Location

🇨🇳 Shanghai, China

ASN

AS4812

Organization

Chinanet SH

Server

Nginx

Nameservers

ns3.51job.com.dns.51job.com.

Performance

Page Speed

22 KB

133 requests

Image Optimization

Lazy Load

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Chinanet SH

Technology Stack

2 Technologies Detected

CSS Frameworks

Tailwind CSS

Web Servers

Nginx

SEO Analysis

D41/100

51job.com51job.com

招聘网_人才网_找工作_求职_上前程无忧

前程无忧人才网面向全国,提供2026准确的招聘网站信息,为企业和求职者提供人才招聘、求职、找工作、培训等在内的全方位的人力资源服务,更多求职找工作信息尽在前程无忧!

Title Length20 chars

Recommended: 50-60 chars

Description Length82 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (129/171)

7 issues found

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Crawlability

Sitemap

robots.txt

22 rules

Allows all crawlers

Sponsored

Security Score

0%Critical

Critical / Transactional

HTTPS

No WAF

377d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

DigiCert, Inc.

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.2

HTTP Protocol

HTTP/1.1

Valid From

27.01.2026

Valid Until

25.02.2027

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.51job.com51job.com

SHA-256 Fingerprint

7E:B2:29:D6:BB:29:AB:F7:17:EF:46:2D:1A:9D:5C:3C:15:8B:09:E1...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

date

Fri, 13 Feb 2026 03:23:15 GMT

content-type

text/html;charset=utf-8

transfer-encoding

chunked

connection

keep-alive

server

nginx

x-http-queqiao

lego

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

MX Records (2)

mxbiz2.qq.com

mxbiz1.qq.com

Domain Information

51job.com

Domain Age

26y 6m

Created

28.07.1999

Expires

28.07.2027

Last Updated

12.02.2024

Registrar

Alibaba Cloud Computing Ltd. d/b/a HiChina (www.net.cn)

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Data Protection Officer mentioned

Typography & Readability

PingFang SC

66/100

Readability

/30

25/40

16px · LH 1.15

Hierarchy

/20

15/25

1x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

PingFang SC

Sans16px

Body Font

PingFang SC

Sans16px

Contrast Ratio

Reading Comfort

Single Font Family

left aligned

16px

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

⚠️ Tight line spacing (1.15). Consider 1.4-1.6 for better readability.

⚠️ 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.

✅ Protected text on images: Using gradient for readability.

Buy on MyFonts

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

13 Resources

Scripts

Styles

Async

Defer

Top Script Sources

js.51jobcdn.com(5)api.geetest.com(2)hm.baidu.com(1)static.geetest.com(1)fecdn.51jobcdn.com(1)

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Last analyzed: 13 Feb 2026 at 03:23

Historical Analysis & Change Tracking