Skip to main content
SGSiteGraph

d3js.org

D3 by Observable | The JavaScript library for bespoke data visualization

Last scanned Jul 25, 2026, 4:25 PM · 2 views

78

Overall score

Fair

Summary

The JavaScript library for bespoke data visualization. This website uses Cloudflare Analytics hosted on Cloudflare behind Cloudflare CDN. SEO is good (75/100) and accessibility is fair (70/100). Security scores fair (65/100) and performance excellent (100/100). Top issue: Title longer than 60 characters.

The JavaScript library for bespoke data visualization

United States
Hosted on Cloudflare

Top issues to fix

9 issues found · 3 high priority

  • Missing Strict-Transport-Security header

    Security

    Add HSTS so browsers always use HTTPS — this closes the protocol-downgrade attack window.

  • Missing Content-Security-Policy header

    Security

    Add a CSP to control which sources can run scripts — the strongest single defense against XSS.

  • Over half of images are missing alt text

    Accessibility

    Add alt attributes to images — screen readers depend on them, and they help image SEO.

  • Missing X-Content-Type-Options header

    Security

    Add X-Content-Type-Options: nosniff to stop MIME-sniffing attacks.

  • Missing X-Frame-Options header

    Security

    Add X-Frame-Options (or a CSP frame-ancestors rule) to prevent clickjacking via hidden iframes.

  • Title longer than 60 characters

    SEO

    Shorten the title to under 60 characters so search results don't truncate it.

+3 more issues — details in the sections below.

75

SEO

4 issue(s) found

100

Performance

649 ms

65

Security

HTTPS & header checks

70

Accessibility

1 issue(s) found

Not enough scan history yet to show a trend — check back after this site has been re-scanned a few more times.

Organization

Company details published in this site's own structured data.

The JavaScript library for bespoke data visualization

Meta tags

Title
D3 by Observable | The JavaScript library for bespoke data visualization
Description
The JavaScript library for bespoke data visualization
Canonical
https://d3js.org
Language
en-US
Charset
utf-8
Viewport
width=device-width,initial-scale=1
Robots meta
Manifest

OpenGraph & Twitter Card

OpenGraph

og:title
og:description
og:type
og:url

Twitter Card

twitter:card
twitter:title
twitter:description

Technologies

Detected frameworks, languages, and tools.

Hosting & CDN

Hosting provider
Cloudflare
CDN provider
Cloudflare
IP address
104.26.6.30
ASN
AS13335 (CLOUDFLARENET - Cloudflare, Inc., US)

DNS records

TypeValue
A
  • 104.26.6.30
  • 104.26.7.30
  • 172.67.73.126
AAAA
  • 2606:4700:20::681a:61e
  • 2606:4700:20::ac43:497e
  • 2606:4700:20::681a:71e
MX
  • eforward3.registrar-servers.com
  • eforward4.registrar-servers.com
  • eforward2.registrar-servers.com
  • eforward1.registrar-servers.com
  • eforward5.registrar-servers.com
TXT
  • v=spf1 include:spf.efwd.registrar-servers.com ~all
  • google-site-verification=5IQxt3Rp9QdGaWGk_wT3dqmsLsnysPRBfxBL5pFRck4
NS
  • cortney.ns.cloudflare.com
  • hans.ns.cloudflare.com
CAA
CNAME
IPv6 supportYes

TLS / SSL certificate

Version
TLS 1.3
Issuer
Google Trust Services
Subject
d3js.org
Valid from
Jul 17, 2026
Valid to
Oct 15, 2026
Days until expiry
81
SAN domains
d3js.org, *.d3js.org

Security headers

  • Strict-Transport-SecurityMissing
  • Content-Security-PolicyMissing
  • X-Frame-OptionsMissing
  • X-Content-Type-OptionsMissing
  • Referrer-PolicyMissing
  • Permissions-PolicyMissing

Compression: gzip · 0 cookie(s) observed

Content & assets

Headings

H1 2 · H2 9 · H3 0

Links

10 internal · 71 external · 0 broken

Images

57 total · 55 missing alt

Scripts / Styles

6 scripts · 1 stylesheets

JS / CSS size

47.9 KB · 0 B

Page size

69.6 KB

Robots.txt & Sitemap

robots.txt
Found
Disallow rules
0
sitemap.xml
Found
URLs in sitemap
116

SEO issues

  • Title longer than 60 characters
  • Multiple H1 headings found
  • No structured data (JSON-LD) found
  • Missing OpenGraph tags

Accessibility issues

  • Over half of images are missing alt text

Scan details

Requested URL
https://d3js.org
Final URL
https://d3js.org
HTTP status
200
HTTP version
HTTP/2
Response time
648 ms
HTML size
69.6 KB
Redirect chain
https://d3js.org

See something wrong on this report? Request a correction

Frequently asked questions

What technology does d3js.org use?
d3js.org is built with Vue.js, Cloudflare Analytics.
Is d3js.org secure (HTTPS)?
Yes. d3js.org uses TLS 1.3 with a certificate issued by Google Trust Services, valid until Oct 15, 2026.
Who hosts d3js.org?
d3js.org is hosted on Cloudflare, behind Cloudflare CDN.
What is d3js.org's SEO score?
d3js.org scored 75/100 for SEO in the latest analysis (fair).
What is d3js.org's overall website score?
d3js.org has an overall SiteGraph score of 78/100, combining SEO, performance, security, and accessibility.