class101.net

https://class101.net· First analyzed 07 May 2026· Updated 07 May 2026

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class101.net

Mobile

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Hosting Provider

Amazon Web Services (AWS)

aws.amazon.com

IP Address

13.33.235.51

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 New York, United States

ASN

AS16509

Organization

AWS CloudFront (GLOBAL)

CDN

CloudFront

Nameservers

ns-1146.awsdns-15.org.ns-1798.awsdns-32.co.uk.ns-49.awsdns-06.com.ns-648.awsdns-17.net.

Performance

Core Web Vitals

Weight

First Contentful Paint

1.3 s10%

Speed Index

1.7 s10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

2.9 MB

148 requests

Image Optimization

Lazy LoadWebPResponsiveFastly Image Optimizer

0–49

50–89

90–100

Architecture Stack

Hybrid

⚙️ SSR

Frontend

Framework

Next.js

CMS

Notion

Infrastructure

Platform

AWS CloudFront

CDN

CloudFront

Technology Stack

7 Technologies Detected

Meta Frameworks

Libraries

Other

CSS Frameworks

Customer Support

Advertising

Security

SEO Analysis

C64/100

Meta Tags13/15

Content2/12

Headings1/8

Technical20/21

E-E-A-T2/7

Images4/7

Links5/5

URL5/5

Social5/5

Freshness0/4

Mobile4/4

Indexability3/3

class101.netclass101.net

CLASS101+ | Learn New Hobbies or Skills Online

South Korea’s #1 online class platform. 6300+ classes. Digital drawing, illustration, crafts & more.

Title Length46 chars

Recommended: 50-60 chars (~271px / 580px)

Description Length100 chars

Recommended: 120-160 chars

Issues (3)

• Very thin content (8 words). Search engines need substantial content for ranking.
• Missing H1 tag — every page should have exactly one H1
• Most images missing alt text (80/97) — critical for accessibility and SEO

4 issues found

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Local SEO

Local Search Readiness

16/100

Poor

4 14

This site doesn't appear to be a local business. Local SEO signals are optional for non-local websites.

Sponsored

AI & LLM Readiness

D40/100

Bot Access

20/25

Machine Read.

7/25

Schema Data

6/25

Citation

7/25

AI Bot Access

14/14 accessible

AI Search

OAI-SearchBot

PerplexityBot

Claude-SearchBot

Gemini-Deep-Research

DuckAssistBot

Training

GPTBot

ClaudeBot

Google-Extended

Meta-ExternalAgent

Bytespiderinfo

Amazonbot

Applebot-Extended

CCBotinfo

Fetch

ChatGPT-User

Machine Readability

llms.txt

llms-full.txt

Semantic HTML

Heading Hierarchy

Text ratio:1%

Words:1,016

Token eff.:Optimal

Structured Data

3 JSON-LD

Organization×1.1WebSite

sameAs entity links

Citation Readiness

Opening Summary

Descriptive Headings

Canonical URL

Open Graph3/3

Twitter Card2/3

Language Tag

Publish Date

Author Info

Lists

Tables

TL;DR / Summary

About Page Link

Recommendations (10)

AI readiness recommendation preview...

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Accessibility

WCAG 2.1 Compliance

Evaluates how accessible your website is for users with disabilities, based on WCAG 2.1 guidelines. Checks images, forms, keyboard navigation, ARIA roles, and color contrast.

72/100

Passed

Critical

Warnings

Images & Alt Text

20/20

Checks if images have descriptive alt text for screen readers and visually impaired users.

Semantic Structure

9/20

Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.

Forms & Inputs

15/15

Verifies form fields have labels, error messages are clear, and inputs are properly associated.

Color & Contrast

15/15

Tests text-to-background color contrast ratios against WCAG AA/AAA minimum requirements.

Keyboard & Focus

11/15

Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).

ARIA & Roles

2/15

Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.

3 recommendations

•Accessibility recommendation preview...

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Carbon Footprint

SWDM v4 · Eco-Score

Carbon emissions estimated using the Sustainable Web Design Model v4 (SWDM v4). Factors in data center, network, and device energy across new and returning visitors. Grade thresholds based on HTTP Archive percentiles.

39/100

299 mg

CO₂e / view

2.9 MB

Page Weight

30%

Cleaner Than

New Visitor

341 mg

Returning (cached)

171 mg

Annual (10K/mo)

35.9 kg

Emission Segments

Data Center

15 mg

Network

88 mg

Device

196 mg

Resource Breakdown

JavaScript

1.3 MB

Images

1.4 MB

CSS

7.5 KB

HTML

231.1 KB

Green Hosting Verified

Amazon Web Services (AWS)

Provider Match

7 recommendations

•Carbon footprint recommendation preview...

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Security Score

21%Critical

Interactive

HTTPS

No WAF

162d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Amazon

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

02.04.2026

Valid Until

16.10.2026

OCSP Stapling

Enabled

Subject Alternative Names (8)

class101.netprivate.class101.net*.class101.jp*.class101.netclass101.co*.private.class101.netclass101.jp*.class101.co

SHA-256 Fingerprint

60:7A:23:2D:92:B2:BB:BA:CE:2D:7A:B5:5F:73:A5:86:62:67:80:EC...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

alt-svc

h3=":443"; ma=86400

cache-control

🔴 No Cache(no-cache)

content-length

236361

content-type

text/html; charset=utf-8

date

Thu, 07 May 2026 16:14:43 GMT

etag

"4cf17-UgyRDJMzUDe2Qm0sOqN3MSFf/aU"

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

DMARC Policy

Quarantine (Moderate)

MX Records (5)

alt2.aspmx.l.google.com

aspmx.l.google.com

aspmx2.googlemail.com

aspmx3.googlemail.com

+1 more

Domain Information

class101.net

Domain Age

8y 2m

Created

01.03.2018

Expires

01.03.2027

Last Updated

25.01.2026

Registrar

Amazon Registrar, Inc.

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

GDPR Indicators

Cookie consent banner detected

Data Protection Officer mentioned

Mobile Compatibility

Viewport & Responsive Test

Tests how well your website works on mobile devices. Checks viewport configuration, responsive layout, touch targets, font readability, and simulates rendering across different screen sizes.

72/100

Mobile Friendly17 breakpoints

Viewport Meta

The viewport meta tag tells mobile browsers how to scale the page. Without it, mobile devices render at desktop width.

Responsive Design

Uses CSS media queries or flexible layouts to adapt content to different screen sizes automatically.

Touch Icons

Apple touch icons and favicons displayed when users add the site to their home screen on mobile devices.

Readable Font Size

Base font size should be at least 16px on mobile to ensure text is readable without zooming.

Relative Units

Using em, rem, %, or vw instead of fixed px values allows content to scale properly across screen sizes.

No H-Scroll Risk

No elements wider than the viewport that would cause horizontal scrolling on mobile devices.

Tap Targets OK

Interactive elements (buttons, links) are at least 48x48px with enough spacing to prevent accidental taps.

No Fixed Widths

No elements with fixed pixel widths that could overflow on smaller screens and break the layout.

Viewport

width=device-width, height=device-height, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no, viewport-fit=cover

2 recommendations

•Mobile compatibility recommendation preview...

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Typography & Readability

Pretendard Variable

WCAG Partial

58/100

Readability

/30

17/30

16px · LH 1.25

Hierarchy

/20

8/20

WCAG

/25

17/25

3.03:1 min contrast

Performance

/25

16/25

1 font

Heading Font

Pretendard Variable

Sans

Body Font

Pretendard Variable

Sans16px

Contrast Ratio

3.03:1

3 issues

Reading Comfort

Single Font Family

left aligned

18px

16px

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

⚠️ Tight line spacing (1.25). Increase to 1.4–1.6 for better readability.

⚠️ Hard to read: Flesch score 39/100. Simplify sentences for wider reach.

⚠️ Partial contrast: 3 elements below WCAG AA threshold (min 3.0:1).

❌ Missing H1: Every page should have exactly one H1 element for SEO and accessibility.

✅ Lean font stack: 1 font families keeps load times fast.

Buy on MyFontsFlesch 39

Color Palette

11 unique colors

Light

#ffffff

Primary· 54.39999999999999%

#617e74

Secondary· 6.9%

#142735

Secondary· 6.7%

#91b0a2

Secondary· 5.6%

#b54e30

Accent· 5.5%

#d1b4a6

Secondary· 4.8%

#f7b453

Accent· 3.7%

#fad7c8

Accent· 3.4%

Business & Marketing Stack

2 Tools Detected

Growing

Customer Support

IntercomMid-Market

Live chat and helpdesk tools

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

22 Resources

Scripts

Styles

Async

Defer

Top Script Sources

local(17)gstatic.com(1)widget.intercom.io(1)polyfill-fastly.io(1)

Website Identity

Class101

Organization

8 years old

Location detected: 🇺🇸 United Statesvia ip

Amazon Registrar, Inc.📧 Google Workspaceen

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Last analyzed: 07 May 2026 at 16:15

Historical Analysis & Change Tracking