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

userapi.com

https://userapi.com· First analyzed 16 Feb 2026· Updated 16 Feb 2026

Export

userapi.com

Mobile

Sponsored

Hosting Provider

Vkontakte Ltd

IP Address

87.240.190.64

Server Location

🇷🇺 St Petersburg, Russia

ASN

AS47541

Organization

Vkontakte Ltd

Server

kittenx

Nameservers

ns4.vkontakte.ru.ns3.vkontakte.ru.ns2.vkontakte.ru.ns1.vkontakte.ru.

Performance

Page Speed

418 KB

55 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Vkontakte Ltd

Technology Stack

3 Technologies Detected

Other

Lottie

Languages

PHPv7.4.125903

Security

reCAPTCHA

SEO Analysis

F11/100

userapi.comuserapi.com

VK | Welcome!

VK is the largest European social network with more than 100 million active users. Our goal is to keep old friends, ex-classmates, neighbors and colleagues i...

Description truncated.

Title Length13 chars

Recommended: 50-60 chars

Description Length165 chars

Recommended: 120-160 chars

Issues (3)

• Missing H1 tag - every page should have one H1
• Many images missing alt text (1/1)
• Missing viewport meta tag - page may not be mobile-friendly

9 issues found

Upgrade to view details

Crawlability

Sitemap

robots.txt

268 rules

Sponsored

Security Score

66%Fair

Interactive

HTTPS

No WAF

380d

Certificate Details

Type

Organization Validated (OV)

Certificate Authority

GlobalSign nv-sa

Key Algorithm

ECDSA (secp384r1) (384 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

30.01.2026

Valid Until

03.03.2027

OCSP Stapling

Enabled

Subject Alternative Names (20)

*.vk.comvk.ruvk.ccvk.mevkontakte.comvkontakte.ruvk.linkvk.design+12 more

SHA-256 Fingerprint

4C:28:49:A6:F1:E1:02:92:0C:39:0F:F4:1F:AB:0A:41:3B:CA:14:12...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

access-control-expose-headers

X-Frontend

cache-control

🔴 No Cache(no-store)

content-encoding

📦 Gzip(gzip)

content-length

40449

content-security-policy

default-src * data: blob: about: vkcalls:;script-src 'self' ...

content-type

text/html; charset=windows-1251

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (1)

mx.vk.com

Domain Information

userapi.com

Domain Age

17y 4m

Created

24.09.2008

Expires

24.09.2026

Last Updated

23.09.2025

Registrar

Regional Network Information Center, JSC dba RU-CENTER

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Data Protection Officer mentioned

Typography & Readability

-apple-system

48/100

Readability

/30

5/40

13px · LH 1.15

Hierarchy

/20

8/25

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

-apple-system

Body Font

-apple-system

Sans13px

Contrast Ratio

Reading Comfort

Single Family

left aligned

❌ Critical: 13px body text is too small. Increase to at least 14px.

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

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

✅ Smart font loading: Using font-display: swap prevents invisible text during load.

✅ Clean layout: Consistent left alignment throughout.

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

30 Resources

Scripts

Styles

Async

Defer

Top Script Sources

st.vk.com(16)local(4)

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Last analyzed: 16 Feb 2026 at 14:33

Historical Analysis & Change Tracking