3blue1brown.com

https://3blue1brown.com· First analyzed 09 May 2026· Updated 09 May 2026

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3blue1brown.com

Mobile

Sponsored

Hosting Provider

Amazon Web Services (AWS)

aws.amazon.com

IP Address

75.2.60.5

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 Seattle, United States

ASN

AS16509

Organization

AWS Global Accelerator (GLOBAL)

Server

Netlify

Nameservers

ns-cloud-a2.googledomains.com.ns-cloud-a3.googledomains.com.ns-cloud-a4.googledomains.com.ns-cloud-a1.googledomains.com.

Performance

100

Core Web Vitals

Weight

First Contentful Paint

522 ms10%

Speed Index

679 ms10%

Largest Contentful Paint

—25%

Total Blocking Time

0.0 ms30%

Cumulative Layout Shift

0.00025%

1.8 MB

53 requests

Image Optimization

WebP

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Styling

Tailwind CSS

CMS

Substack

Infrastructure

Platform

Netlify

Technology Stack

4 Technologies Detected

Analytics

CSS Frameworks

Platforms

SEO Analysis

D59/100

Meta Tags8/15

Content5/12

Headings6/8

Technical18/25

E-E-A-T0/7

Images2/7

Links5/5

URL5/5

Social3/5

Freshness0/4

Mobile4/4

Indexability3/3

3blue1brown.com3blue1brown.com

3Blue1Brown

Mathematics with a distinct visual perspective. Linear algebra, calculus, neural networks, topology, and more.

Title Length11 chars

Recommended: 50-60 chars (~66px / 580px)

Description Length110 chars

Recommended: 120-160 chars

Issues (1)

• Most images missing alt text (22/23) — critical for accessibility and SEO

6 issues found

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Crawlability

Sitemap

Type: standard

198 URLs

robots.txt

3 rules

Sitemap reference found

Allows all crawlers

Local SEO

Local Search Readiness

3/100

Poor

1 14 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

F38/100

Bot Access

20/25

Machine Read.

7/25

Schema Data

0/25

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

navheader/footer

Text ratio:2%

Words:237

Token eff.:Too Short

Sections/1K:16.9

Depth:2/5

Structured Data

No Schema

Citation Readiness

Opening Summary12w

Descriptive Headingsavg 1w

Canonical URL

Open Graph3/3

Twitter Card0/3

Language Tag

Publish Date

Author Info

Lists

Tables

TL;DR / Summary

About Page Link

Recommendations (9)

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.

80/100

Passed

Critical

Warnings

Images & Alt Text

20/20

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

Semantic Structure

18/20

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

11/15

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

ARIA & Roles

6/15

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

1 recommendation

•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.

60/100

183 mg

CO₂e / view

1.8 MB

Page Weight

60%

Cleaner Than

New Visitor

210 mg

Returning (cached)

105 mg

Annual (10K/mo)

22.0 kg

Emission Segments

Data Center

9 mg

Network

54 mg

Device

121 mg

Resource Breakdown

JavaScript

940.2 KB

Images

777.0 KB

CSS

79.8 KB

HTML

17.3 KB

Other

1.2 KB

Green Hosting Verified

Amazon Web Services (AWS)

Provider Match

4 recommendations

•Carbon footprint recommendation preview...

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Security Score

36%Critical

Interactive

HTTPS

No WAF

43d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Let's Encrypt

Key Algorithm

ECDSA (secp256r1) (256 bit)

Signature

ECDSA with SHA-384

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2

Valid From

23.03.2026

Valid Until

21.06.2026

Subject Alternative Names (7)

3b1b.co3blue1brown.comgrantsanderson.comwww.3b1b.cowww.3b1b.comwww.3blue1brown.comwww.grantsanderson.com

SHA-256 Fingerprint

C8:8A:28:E6:B2:90:26:09:C6:EE:07:11:BC:12:3F:31:3C:E9:9C:53...

Top Recommendations

Security recommendation preview

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HTTP Headers

Developer Console

accept-ranges

bytes

age

23057

cache-control

🟡 0s(public,max-age=0,must-revalidate)

cache-status

"Netlify Edge"; hit

content-encoding

⚡ Brotli(br)

content-length

17371

Good Warning Issue

Email Infrastructure

Google Workspace

Score

SPF

DKIM

DMARC

MX Records (5)

alt1.aspmx.l.google.com

alt3.aspmx.l.google.com

alt4.aspmx.l.google.com

alt2.aspmx.l.google.com

+1 more

Domain Information

3blue1brown.com

Domain Age

11y 2m

Created

04.03.2015

Expires

04.03.2027

Last Updated

17.02.2026

Registrar

Squarespace Domains II LLC

DNSSEC

Not Enabled

Privacy & Compliance

Cookie Consent Banner

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.

69/100

Mobile Friendly1 breakpoint

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...

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Typography & Readability

Figtree Variable + Source Serif 4 Variable

64/100

Readability

/30

17/30

17px · LH 2.00

Hierarchy

/20

10/20

1.88x ratio

WCAG

/25

19/25

Performance

/25

18/25

2 fonts · 2 req

Heading Font

Figtree Variable

Sans32px

Body Font

Source Serif 4 Variable

Serif17px

Contrast Ratio

Reading Comfort

~34 CPL

Narrow lines

32px

25px

17px

✅ Excellent readability: 17px body text is ideal for all devices.

⚠️ Wide line spacing (2.00). 1.4–1.6 is optimal for body text.

⚠️ Hard to read: Flesch score 37/100. Simplify sentences for wider reach.

⚠️ Minor heading issue: 0 level skip(s) detected. Maintain sequential order for screen readers.

✅ Lean font stack: 2 font families keeps load times fast.

✅ Smart font loading: font-display: swap prevents invisible text during load (FOIT).

Buy on MyFontsFlesch 37

Color Palette

9 unique colors

6.12:1 AA Dark

#000000

Text· 50.6%

#918a7a

Secondary· 6.4%

#fbf0de

Primary· 9.8%

#dbcfba

Secondary· 7.1%

#b2a997

Secondary· 6.2%

#655f52

Secondary· 5.5%

#ece0ca

Secondary· 3.3%

Business & Marketing Stack

1 Tools Detected

Growing

Behavior Analytics

Google AnalyticsFree

User behavior and product analytics

Sponsored

Scripts & Styles

10 Resources

Scripts

Styles

Async

Defer

Top Script Sources

googletagmanager.com(2)cdn.jsdelivr.net(2)

Website Identity

3blue1brown.com

11 years old

Location detected: 🇺🇸 United Statesvia ip

Squarespace Domains II LLC📧 Google Workspaceen

Social Profiles

Facebook X (Twitter)Instagram GitHub TikTok Reddit Bluesky

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Last analyzed: 09 May 2026 at 05:50

Historical Analysis & Change Tracking