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exercism.io

https://exercism.io· First analyzed 01 May 2026· Updated 01 May 2026
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exercism.io
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Mobile

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Hosting Provider

Cloudflare
cloudflare.com

IP Address

172.67.221.30

Site Location

🇨🇦 Canadavia ip

Server Location

🇨🇦 Toronto, Canada

ASN

AS13335

Organization

Cloudflare, Inc.

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

gabriel.ns.cloudflare.com.suzanne.ns.cloudflare.com.

Performance

99

Core Web Vitals

Weight

First Contentful Paint
846 ms10%
Speed Index
1.1 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
10 KB
68 requests

Image Optimization

WebPResponsive
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Hosting
Cloudflare
CDN
Cloudflare

Progressive Web App

Web ManifestApple Touch Icon

Technology Stack

2 Technologies Detected

CSS Frameworks

1
Tailwind CSS

CDN

1
Cloudflare

SEO Analysis

C68/100
20
5
1
Meta Tags7/15
Content11/12
Headings7/8
Technical18/25
E-E-A-T0/7
Images3/7
Links5/5
URL5/5
Social5/5
Freshness0/4
Mobile4/4
Indexability3/3
E
exercism.ioexercism.io

Exercism

Learn, practice and get world-class mentoring in over 50 languages. 100% free.

Title Length8 chars

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

Description Length78 chars

Recommended: 120-160 chars

Issues (1)

  • • Most images missing alt text (38/66) — critical for accessibility and SEO

6 issues found

Upgrade to view details

Crawlability

Sitemap

Type: index

84 URLs

84 sub-sitemaps

robots.txt

22 rules

Local SEO

Local Search Readiness

6/100
Poor
2 13 2

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

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AI & LLM Readiness

D43/100
Bot Access
15/25
Machine Read.
12/25
Schema Data
0/25
Citation
16/25

AI Bot Access

6/14 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
navheader/footer
Text ratio:11%
Words:844
Token eff.:Optimal
Sections/1K:26.1
Depth:2/5

Structured Data

No Schema

Citation Readiness

Opening Summary23w
Descriptive Headingsavg 4.3w
Canonical URL
Open Graph3/3
Twitter Card3/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (7)
AI readiness recommendation preview...
Upgrade to view recommendations

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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.
C
69/100
9
Passed
4
Critical
1
Warnings
Images & Alt Text
15/20
Checks if images have descriptive alt text for screen readers and visually impaired users.
Semantic Structure
17/20
Evaluates proper use of HTML5 semantic elements (header, nav, main, footer) and heading hierarchy.
Forms & Inputs
10/15
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
9/15
Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).
ARIA & Roles
3/15
Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
3 recommendations
  • •Accessibility recommendation preview...
Upgrade to view recommendations

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.
78/100
A+
1 mg
CO₂e / view
10.5 KB
Page Weight
95%
Cleaner Than
New Visitor
1 mg
vs
Returning (cached)
<0.001 g
Annual (10K/mo)
132 g
Emission Segments
Data Center
<0.001 g
Network
<0.001 g
Device
<0.001 g
Resource Breakdown
HTML
10.5 KB
Green Hosting Verified
Cloudflare
GWF Verified
2 recommendations
  • •Carbon footprint recommendation preview...
Upgrade to view recommendations
A+

Security Score

93%Excellent
Static / Informational

HTTPS

WAF

82d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Google Trust Services

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-256

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

24.04.2026

Valid Until

23.07.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

exercism.org*.exercism.org

SHA-256 Fingerprint

71:7A:B3:F0:87:DB:81:3C:E0:1F:2D:61:1A:20:90:44:12:CB:90:AE...

Recommendations

Security recommendation preview

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Upgrade to view header details

HTTP Headers

Developer Console

age
944
cache-control
🟡 4 Hours(public, max-age=14400, no-transform)
cf-cache-status
HIT
cf-ray🇫🇷 Paris
9f51b2857a8f069a-CDG
content-encoding
📦 Gzip(gzip)
content-security-policy-report-only
default-src 'self' https://exercism.org https://api.exercism...
Good Warning Issue

Email Infrastructure

Google Workspace

Score

90

SPF
DKIM
DMARC

DMARC Policy

None (Monitor Only)

MX Records (5)

aspmx.l.google.com
alt2.aspmx.l.google.com
alt1.aspmx.l.google.com
alt3.aspmx.l.google.com

+1 more

Domain Information

exercism.io

Domain Age
12y 11m

Created

02.06.2013

Expires

02.06.2027

Last Updated

28.04.2026

Registrar

Gandi SAS

DNSSEC
Not Enabled

Privacy & Compliance

Cookie Consent Banner
Privacy Policy
Terms of Service

GDPR Indicators

Privacy policy page linked

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.
B
70/100
Mobile Friendly
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, initial-scale=1
2 recommendations
  • •Mobile compatibility recommendation preview...
Upgrade to view recommendations

Typography & Readability

Poppins

WCAG AA
81/100
Readability
/30
24/30

16px · LH 1.60

Hierarchy
/20
20/20

3x ratio · ✓ H1→H6

WCAG
/25
21/25

4.81:1 min contrast

Performance
/25
16/25

1 font · 7 req

Heading Font

Poppins

Sans48px

Body Font

Poppins

Sans16px

Contrast Ratio

4.81:1

WCAG AA (≥4.5:1)

Reading Comfort

~37 CPL

Narrow lines
48px
h1
39px
h2
31px
h3
16px
p

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

✅ Optimal line spacing: 1.60 ratio (ideal range 1.4–1.6).

✅ WCAG AA contrast: All text meets 4.5:1 ratio (min 4.8:1).

✅ Perfect heading hierarchy: Sequential h1→h2→h3 with single H1 — ideal for SEO & accessibility.

✅ Strong hierarchy: Headlines are 3.0x larger than body text.

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

Buy on MyFontsFlesch 57

Color Palette

5 unique colors
Light
#ffffff
Background· 78.69999999999999%
#130b43
Primary· 6%
#e5eae6
Secondary· 5.5%
#77628c
Secondary· 5.1%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

1
Google AnalyticsFree

User behavior and product analytics

1

Categories

1

Total Tools

0

Enterprise

0

Mid-Market

Assessment: Growing marketing technology adoption

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Scripts & Styles

4 Resources

2
Scripts
2
Styles
0
Async
2
Defer

Top Script Sources

assets.exercism.org(1)static.cloudflareinsights.com(1)

Website Identity

exercism.io

12 years old
Location detected: 🇨🇦 Canadavia ip
Gandi SAS📧 Google Workspaceen-US

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Last analyzed: 01 May 2026 at 20:57

Historical Analysis & Change Tracking