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c3js.org

https://c3js.org· First analyzed 19 May 2026· Updated 19 May 2026
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c3js.org
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Hosting Provider

GitHub Pages
pages.github.com

IP Address

185.199.108.153

Site Location

🇺🇸 United Statesvia ip

Server Location

🇺🇸 San Francisco, United States

ASN

AS54113

Organization

GitHub, Inc

Server

GitHub.com

CDN

Fastly

Nameservers

ns-1633.awsdns-12.co.uk.ns-506.awsdns-63.com.ns-800.awsdns-36.net.ns-1155.awsdns-16.org.

Performance

97

Core Web Vitals

Weight

First Contentful Paint
1.0 s10%
Speed Index
1.3 s10%
Largest Contentful Paint
—25%
Total Blocking Time
0.0 ms30%
Cumulative Layout Shift
0.00025%
228 KB
16 requests
0–49
50–89
90–100

Architecture Stack

Monolithic
⚙️ SSR
Infrastructure
Platform
GitHub Pages
CDN
Fastly

Technology Stack

8 Technologies Detected

CSS Frameworks

3
Tailwind CSS
Normalize.cssFoundation

Analytics

2
Google Analytics
Segment

Libraries

1
jQueryv1.11.0

Other

1
D3.js

Other

1
Modernizr

SEO Analysis

D54/100
14
9
0
Meta Tags8/15
Content11/12
Headings6/8
Technical9/21
E-E-A-T3/7
Images0/7
Links5/5
URL5/5
Social0/5
Freshness0/4
Mobile4/4
Indexability3/3
C
c3js.orgc3js.org

C3.js | D3-based reusable chart library

D3 based reusable chart library

Title Length39 chars

Recommended: 50-60 chars (~230px / 580px)

Description Length31 chars

Recommended: 120-160 chars

Issues (0)

    9 issues found

    Upgrade to view details

    Local SEO

    Local Search Readiness

    5/100
    Poor
    1 14 2

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

    Sponsored

    AI & LLM Readiness

    D41/100
    Bot Access
    20/25
    Machine Read.
    14/25
    Schema Data
    0/25
    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
    nav
    Text ratio:17%
    Words:858
    Token eff.:Optimal
    Sections/1K:10.5
    Depth:1/5

    Structured Data

    No Schema

    Citation Readiness

    Opening Summary31w
    Descriptive Headingsavg 2.2w
    Canonical URL
    Open Graph0/3
    Twitter Card0/3
    Language Tag
    Publish Date
    Author Info
    Lists
    Tables
    TL;DR / Summary
    About Page Link
    Recommendations (9)
    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
    73/100
    8
    Passed
    4
    Critical
    0
    Warnings
    Images & Alt Text
    20/20
    Checks if images have descriptive alt text for screen readers and visually impaired users.
    Semantic Structure
    13/20
    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
    9/15
    Ensures all interactive elements are reachable and operable via keyboard (tab, enter, escape).
    ARIA & Roles
    1/15
    Checks correct use of WAI-ARIA attributes (roles, states, properties) for assistive technologies.
    2 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.
    62/100
    A+
    28 mg
    CO₂e / view
    228.3 KB
    Page Weight
    95%
    Cleaner Than
    New Visitor
    32 mg
    vs
    Returning (cached)
    16 mg
    Annual (10K/mo)
    3.4 kg
    Emission Segments
    Data Center
    6 mg
    Network
    7 mg
    Device
    15 mg
    Resource Breakdown
    JavaScript
    192.7 KB
    Images
    7.7 KB
    CSS
    23.5 KB
    HTML
    4.4 KB
    Green Hosting Not Verified
    GitHub Pages
    3 recommendations
    • •Carbon footprint recommendation preview...
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    B

    Security Score

    71%Good
    Static / Informational

    HTTPS

    No WAF

    64d

    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

    24.04.2026

    Valid Until

    23.07.2026

    Subject Alternative Names (1)

    c3js.org

    SHA-256 Fingerprint

    45:2B:FD:E2:7B:64:5A:E7:C2:F0:99:82:66:25:46:EB:46:9F:AC:6E...

    Recommendations

    Security recommendation preview

    Upgrade to view recommendations
    Upgrade to view header details

    HTTP Headers

    Developer Console

    accept-ranges
    bytes
    access-control-allow-origin
    *
    age
    0
    cache-control
    🟡 600s(max-age=600)
    content-encoding
    📦 Gzip(gzip)
    content-length
    4204
    Good Warning Issue

    Email Infrastructure

    Custom Mail Server

    Score

    0

    SPF
    DKIM
    DMARC

    Domain Information

    c3js.org

    Domain Age
    12y 9m

    Created

    10.08.2013

    Expires

    10.08.2026

    Last Updated

    30.07.2025

    Registrar

    GMO Internet Group, Inc. d/b/a Onamae.com

    DNSSEC
    Not Enabled

    Privacy & Compliance

    Cookie Consent Banner
    Privacy Policy
    Terms of Service

    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.
    C
    61/100
    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
    1 recommendation
    • •Mobile compatibility recommendation preview...
    Upgrade to view recommendations

    Typography & Readability

    Helvetica Neue

    WCAG Partial
    77/100
    Readability
    /30
    25/30

    16px · LH 1.60

    Hierarchy
    /20
    13/20

    2.75x ratio

    WCAG
    /25
    17/25

    1.26:1 min contrast

    Performance
    /25
    22/25

    System fonts

    Heading Font

    Helvetica Neue

    Sans44px

    Body Font

    Helvetica Neue

    Sans16px

    Contrast Ratio

    1.26:1

    23 issues

    Reading Comfort

    ~37 CPL

    Narrow lines
    44px
    h1
    37px
    h2
    27px
    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).

    ✅ Easy to read: Flesch score 70/100 — accessible to general audiences.

    ⚠️ Partial contrast: 23 elements below WCAG AA threshold (min 1.3:1).

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

    ✅ Strong hierarchy: Headlines are 2.8x larger than body text.

    Flesch 71

    Color Palette

    6 unique colors
    12.42:1 AAA Light
    #fdfdfd
    Background· 88.9%
    #333333
    Other· 5.1%
    #c5ced0
    Primary· 2.2%
    #6598a9
    Secondary· 1.9%

    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

    Scripts & Styles

    14 Resources

    8
    Scripts
    6
    Styles
    1
    Async
    0
    Defer

    Top Script Sources

    local(7)google-analytics.com(1)

    Website Identity

    c3js.org

    12 years old
    Location detected: 🇺🇸 United Statesvia ip
    GMO Internet Group, Inc. d/b/a Onamae.com

    Social Profiles

    GitHub

    Sponsored

    Last analyzed: 19 May 2026 at 23:20

    Historical Analysis & Change Tracking