StackOptic
Back to Search
redblobgames.com favicon

redblobgames.com

https://redblobgames.com· First analyzed 06 May 2026· Updated 06 May 2026
Export
redblobgames.com
Desktop screenshot of redblobgames.com
Mobile screenshot of redblobgames.com
Mobile

Sponsored

Hosting Provider

Amazon Web Services (AWS)
aws.amazon.com

IP Address

34.198.241.65

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 Ashburn, United States

ASN

AS14618

Organization

AWS EC2 (us-east-1)

Server

Nginx

Nameservers

ns-578.awsdns-08.net.ns-1303.awsdns-34.org.ns-1703.awsdns-20.co.uk.ns-409.awsdns-51.com.

Performance

100

Core Web Vitals

Weight

First Contentful Paint
407 ms10%
Speed Index
529 ms10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
431 KB
45 requests
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Blogger

Technology Stack

4 Technologies Detected

Frameworks

1
Vue.js

Other

1
D3.js

CSS Frameworks

1
Tailwind CSS

Web Servers

1
Nginx

SEO Analysis

B72/100
20
6
1
Meta Tags5/15
Content11/12
Headings8/8
Technical21/25
E-E-A-T5/7
Images1/7
Links5/5
URL5/5
Social4/5
Freshness0/4
Mobile4/4
Indexability3/3
R
redblobgames.comredblobgames.com

Red Blob Games

Interactive tutorials for math and algorithms

Title Length14 chars

Recommended: 50-60 chars (~90px / 580px)

Description Length45 chars

Recommended: 120-160 chars

Issues (1)

  • • Most images missing alt text (41/43) — critical for accessibility and SEO

7 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

354 URLs

robots.txt

6 rules

Sitemap reference found

Allows all crawlers

Local SEO

Local Search Readiness

14/100
Poor
4 12 1

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

Sponsored

AI & LLM Readiness

D46/100
Bot Access
20/25
Machine Read.
12/25
Schema Data
3/25
Citation
11/25

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
header/footer
Text ratio:17%
Words:1,121
Token eff.:Optimal
Sections/1K:4.5
Depth:1/5

Structured Data

Microdata
Organization×1.1microdata
sameAs entity links

Citation Readiness

Opening Summary16w
Descriptive Headingsavg 1.2w
Canonical URL
Open Graph3/3
Twitter Card1/3
Language Tag
Publish Date
Author Info
Lists
Tables
TL;DR / Summary
About Page Link
Recommendations (10)
AI readiness recommendation preview...
Upgrade to view recommendations

Sponsored

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.
B
78/100
11
Passed
2
Critical
1
Warnings
Images & Alt Text
20/20
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
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
0/15
Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
1 recommendation
  • •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.
71/100
A
44 mg
CO₂e / view
431.1 KB
Page Weight
90%
Cleaner Than
New Visitor
50 mg
vs
Returning (cached)
25 mg
Annual (10K/mo)
5.2 kg
Emission Segments
Data Center
2 mg
Network
13 mg
Device
29 mg
Resource Breakdown
Images
416.8 KB
CSS
1.6 KB
HTML
12.7 KB
Green Hosting Verified
Amazon Web Services (AWS)
Provider Match
2 recommendations
  • •Carbon footprint recommendation preview...
Upgrade to view recommendations
A

Security Score

81%Very Good
Static / Informational

HTTPS

No WAF

73d

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

19.04.2026

Valid Until

18.07.2026

Subject Alternative Names (2)

redblobgames.comwww.redblobgames.com

SHA-256 Fingerprint

5E:02:FE:33:07:B0:66:7A:86:6E:7E:D6:A0:DE:97:17:10:55:8D:1F...

Recommendations

Security recommendation preview

Upgrade to view recommendations
Upgrade to view header details

HTTP Headers

Developer Console

cache-control
🟡 0s(max-age=0, public)
content-encoding
⚡ Brotli(br)
content-security-policy
frame-ancestors http: https: filesystem:; object-src 'none';...
content-type
text/html; charset=UTF-8
date
Wed, 06 May 2026 12:27:14 GMT
etag
W/"69f78709-a752"
Good Warning Issue

Email Infrastructure

Custom Mail Server

Score

95

SPF
DKIM
DMARC

DMARC Policy

Reject (Strictest)

MX Records (2)

spool.mail.gandi.net
fb.mail.gandi.net

Domain Information

redblobgames.com

Domain Age
14y 7m

Created

28.09.2011

Expires

28.09.2032

Last Updated

13.06.2025

Registrar

Gandi SAS

DNSSEC
Not Enabled

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
76/100
Mobile Friendly9 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, initial-scale=1
1 recommendation
  • •Mobile compatibility recommendation preview...
Upgrade to view recommendations

Typography & Readability

Avenir Next + Iowan Old Style

WCAG Partial
75/100
Readability
/30
25/30

20px · LH 1.50

Hierarchy
/20
20/20

3x ratio · ✓ H1→H6

WCAG
/25
14/25

1:1 min contrast

Performance
/25
16/25

2 fonts

Heading Font

Avenir Next

Sans60px

Body Font

Iowan Old Style

Sans20px

Contrast Ratio

1:1

2 issues

Reading Comfort

~45 CPL

Optimal (45–75)
60px
h1
25px
h2
48px
h3
20px
p
Minor Third
Scale

✅ Excellent readability: 20px body text is ideal for all devices.

✅ Optimal line spacing: 1.50 ratio (ideal range 1.4–1.6).

✅ Optimal line length: ~45 chars/line (ideal 45–75 CPL).

⚠️ Hard to read: Flesch score 31/100. Simplify sentences for wider reach.

⚠️ Partial contrast: 2 elements below WCAG AA threshold (min 1.0:1).

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

Buy on MyFontsFlesch 31

Color Palette

9 unique colors
2.35:1 Fail Light
#eeeeee
Background· 47.09999999999999%
#9a9e95
Other· 5.4%
#90201f
Accent· 9.9%
#a23534
Primary· 7.1%
#cdbfbc
Secondary· 6.1%
#5d4551
Secondary· 3.8%
#4c151c
Accent· 3.6%

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

Sponsored

Website Identity

redblobgames.com

redblobgames@gmail.com
14 years old

Copyright ©2026Red Blob GamesRSS Feed

Location detected: 🇺🇸 United Statesvia ip
Gandi SASen

Sponsored

Last analyzed: 06 May 2026 at 12:27

Historical Analysis & Change Tracking