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

groups.io

https://groups.io· First analyzed 17 Feb 2026· Updated 17 Feb 2026

Export

groups.io

Sponsored

Hosting Provider

Linode (Akamai)

linode.com

IP Address

173.255.221.194

Server Location

🇺🇸 Fremont, United States

ASN

AS63949

Organization

Linode

Server

Nginx

Nameservers

dns2.groups.io.dns1.groups.io.

Performance

Page Speed

2.6 MB

28 requests

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Infrastructure

Hosting

Linode (Akamai)

Progressive Web App

Web ManifestApple Touch Icon

Technology Stack

6 Technologies Detected

Analytics

Libraries

CSS Frameworks

Icon Libraries

Web Servers

SEO Analysis

D52/100

groups.iogroups.io

Groups.io | Email Discussion Groups & Listserv Alternative

Groups.io is a modern email group service and listserv alternative with no ads. Create mailing lists with calendars, files, wikis, and more. Better than Goog...

Description truncated.

Title Length58 chars

Recommended: 50-60 chars

Description Length183 chars

Recommended: 120-160 chars

Issues (1)

• Missing H1 tag - every page should have one H1

6 issues found

Upgrade to view details

Sponsored

Security Score

20%Critical

Critical / Transactional

HTTPS

No WAF

84d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

12.02.2026

Valid Until

13.05.2026

Subject Alternative Names (1)

groups.io

SHA-256 Fingerprint

D8:64:E3:7B:32:CF:0F:ED:4D:49:AC:A5:FD:46:39:57:16:68:17:2F...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

accept-ch

Sec-CH-UA-Platform, Sec-CH-UA-Platform-Version, Sec-CH-UA-Mo...

content-encoding

📦 Gzip(gzip)

content-security-policy

frame-ancestors 'self';

content-type

text/html; charset=utf-8

critical-ch

Sec-CH-UA-Platform, Sec-CH-UA-Platform-Version

date

Tue, 17 Feb 2026 03:14:37 GMT

Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

SPF

DKIM

DMARC

DMARC Policy

None (Monitor Only)

MX Records (2)

lb01.groups.io

lb02.groups.io

Domain Information

groups.io

Domain Age

15y 3m

Created

08.11.2010

Expires

08.11.2027

Last Updated

04.11.2025

Registrar

Gandi SAS

DNSSEC

Not Enabled

Privacy & Compliance

Cookiebot

Cookie Consent Banner

Cookiebot

GDPR Indicators

Cookie consent banner detected

CMP: Cookiebot

Typography & Readability

system-ui

90/100

Readability

/30

40/40

16px · LH 1.43

Hierarchy

/20

25/25

6x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

20/20

System fonts

Heading Font

system-ui

Sans96px

Body Font

system-ui

Sans16px

Contrast Ratio

Reading Comfort

~38 CPL

Needs attention

96px

30px

22px

18px

16px

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

✅ Optimal line spacing: 1.43 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 6.0x larger than body text.

✅ 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.

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

7 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(4)

Website Identity

Bluesky

Sponsored

Last analyzed: 17 Feb 2026 at 03:14

Historical Analysis & Change Tracking