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SGSiteGraph

nextstrain.org

Nextstrain

Last scanned Aug 24, 2026, 1:22 PM

84

Overall score

Great

Summary

Real-time tracking of pathogen evolution. This website uses Next.js hosted on AWS. SEO is good (85/100) and accessibility is excellent (100/100). Security scores fair (65/100) and performance excellent (90/100). Top issue: Missing canonical link.

Real-time tracking of pathogen evolution

United States
Hosted on AWS

Top issues to fix

7 issues found · 2 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.

  • 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.

  • Missing canonical link

    SEO

    Add <link rel="canonical"> so search engines know which URL variant to index.

  • Multiple H1 headings found

    SEO

    Keep a single H1 per page and demote the others to H2/H3.

+1 more issue — details in the sections below.

85

SEO

3 issue(s) found

90

Performance

190 ms

65

Security

HTTPS & header checks

100

Accessibility

0 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.

Real-time tracking of pathogen evolution

Contact

Email, phone, and address published on this site's own pages.

Meta tags

Title
Nextstrain
Description
Real-time tracking of pathogen evolution
Canonical
Language
en
Charset
utf-8
Viewport
width=device-width, initial-scale=1
Robots meta
Manifest

OpenGraph & Twitter Card

OpenGraph

og:title
Nextstrain
og:description
Real-time tracking of pathogen evolution
og:type
website
og:url
https://nextstrain.org

Twitter Card

twitter:card
summary_large_image
twitter:title
Nextstrain
twitter:description
Real-time tracking of pathogen evolution

Technologies

Detected frameworks, languages, and tools.

Hosting & CDN

Hosting provider
AWS
CDN provider
IP address
35.71.150.51
ASN
AS16509 (AMAZON-02 - Amazon.com, Inc., US)

DNS records

TypeValue
A
  • 35.71.150.51
  • 3.33.161.45
  • 15.197.152.254
  • 13.248.131.213
AAAA
MX
  • in1-smtp.messagingengine.com
  • in2-smtp.messagingengine.com
TXT
  • google-site-verification=MKfOapfIvt4U2tExw9vc3xCZGB_-Hvq4TYd8NVZDOmg
  • google-site-verification=5d_PLzfcFSRO1TQ5T4v1WdEGS2xf9T_7Gk9AQXsYeRI
  • v=spf1 include:spf.messagingengine.com include:spf.zoho.com include:transmail.net include:amazonses.com -all
  • google-site-verification=Xkfn_pf5ryuQGElxu6kU_0P457nPp64lg7X5P0wUZ44
NS
  • ns4.dnsimple.com
  • ns3.dnsimple.com
  • ns2.dnsimple.com
  • ns1.dnsimple.com
CAA
CNAME
IPv6 supportNo

TLS / SSL certificate

Version
TLS 1.3
Issuer
Let's Encrypt
Subject
nextstrain.org
Valid from
Jul 7, 2026
Valid to
Oct 5, 2026
Days until expiry
41
SAN domains
nextstrain.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 3 · H2 4 · H3 4

Links

39 internal · 34 external · 0 broken

Images

85 total · 0 missing alt

Scripts / Styles

20 scripts · 2 stylesheets

JS / CSS size

518 KB · 56.9 KB

Page size

76.2 KB

Robots.txt & Sitemap

robots.txt
Found
Disallow rules
0
sitemap.xml
Not found
URLs in sitemap
0

SEO issues

  • Missing canonical link
  • Multiple H1 headings found
  • sitemap.xml not found

Accessibility issues

No accessibility issues detected.

Scan details

Requested URL
https://nextstrain.org
Final URL
https://nextstrain.org
HTTP status
200
HTTP version
HTTP/2
Response time
189 ms
HTML size
76.2 KB
Redirect chain
https://nextstrain.org

See something wrong on this report? Request a correction

Frequently asked questions

What technology does nextstrain.org use?
nextstrain.org is built with Next.js, Express, Node.js, Plausible Analytics.
Is nextstrain.org secure (HTTPS)?
Yes. nextstrain.org uses TLS 1.3 with a certificate issued by Let's Encrypt, valid until Oct 5, 2026.
Who hosts nextstrain.org?
nextstrain.org is hosted on AWS.
What is nextstrain.org's SEO score?
nextstrain.org scored 85/100 for SEO in the latest analysis (great).
What is nextstrain.org's overall website score?
nextstrain.org has an overall SiteGraph score of 84/100, combining SEO, performance, security, and accessibility.