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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feishu.cn

https://feishu.cn· First analyzed 13 Feb 2026· Updated 13 Feb 2026

Export

feishu.cn

Mobile

Sponsored

Hosting Provider

BeiJing Teamsun Technology Co.

IP Address

122.14.236.76

Server Location

🇨🇳 Beijing, China

ASN

AS9808

Organization

BeiJing Teamsun Technology Co.

Server

TLB

Nameservers

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

Performance

Page Speed

3.6 MB

143 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Ghost

Technology Stack

7 Technologies Detected

Customer Support

Other

CSS Frameworks

Analytics

Tag Managers

Marketing

SEO Analysis

B70/100

feishu.cnfeishu.cn

Lark | Productivity Superapp for Chat, Meetings, Docs & Projects

Lark is a productivity superapp for teams. Get chat, docs, meetings, workflow automations & AI for free all in one place.

Title Length64 chars

Recommended: 50-60 chars

Description Length121 chars

Recommended: 120-160 chars

Issues (1)

• Many images missing alt text (215/215)

3 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

robots.txt

1 rules

Allows all crawlers

Sponsored

Security Score

21%Critical

Interactive

HTTPS

No WAF

53d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

DigiCert Inc

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-256

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

08.04.2025

Valid Until

07.04.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.larksuite.comlarksuite.com

SHA-256 Fingerprint

DC:C6:B5:8C:44:5E:A2:C6:58:ED:BA:8D:6A:36:BA:21:D6:20:8C:9A...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

content-type

text/html; charset=utf-8

x-envoy-response-flags

to-env

x-lgw-dst-svc

EfbIg0NqhxHkPfgRSFibODGSuag73Luc5DiKrAA4gvKIl_V7vETZEJSl6k8E...

tt_stable

x-request-id

20260213202637459399EB072FD9590608

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

MX Records (3)

mx2.feishu.cn

mx1.feishu.cn

mx3.feishu.cn

Domain Information

feishu.cn

DNSSEC

Not Enabled

Privacy & Compliance

Cookiebot

Cookie Consent Banner

Cookiebot

GDPR Indicators

Cookie consent banner detected

CMP: Cookiebot

Data Protection Officer mentioned

Typography & Readability

Helvetica Neue

70/100

Readability

/30

32/40

18px · LH 1.33

Hierarchy

/20

15/25

0.89x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

2 fonts

Heading Font

Helvetica Neue

Sans16px

Body Font

Helvetica Neue

Sans18px

Contrast Ratio

Reading Comfort

~41 CPL

Needs attention

16px

36px

20px

18px

Augmented Fourth

Scale

✅ Excellent readability: 18px body text is ideal for all devices.

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

✅ Good performance: Using 2 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.

✅ Protected text on images: Using gradient for readability.

Buy on MyFonts

Business & Marketing Stack

4 Tools Detected

Advanced

Customer Support

IntercomMid-Market

ZendeskEnterprise

Live chat and helpdesk tools

Behavior Analytics

Google Tag ManagerFree

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

16 Resources

Scripts

Styles

Async

Defer

Top Script Sources

sf16-sg.larksuitecdn.com(4)lf-package-sg.larksuitecdn.com(4)accounts.google.com(2)sf16-short-sg.bytedapm.com(2)widget.intercom.io(1)

Website Identity

Facebook X (Twitter)Instagram LinkedIn TikTok

Sponsored

Last analyzed: 13 Feb 2026 at 12:27

Historical Analysis & Change Tracking