What technology does substackcdn.com use?

We did not detect any specific technologies for substackcdn.com in the latest scan.

Is substackcdn.com secure (HTTPS)?

Yes. substackcdn.com uses TLS 1.3 with a certificate issued by Amazon, valid until Jan 12, 2027.

Who hosts substackcdn.com?

substackcdn.com is hosted on AWS, behind CloudFront CDN.

What is substackcdn.com's SEO score?

substackcdn.com scored 55/100 for SEO in the latest analysis (fair).

What is substackcdn.com's overall website score?

substackcdn.com has an overall SiteGraph score of 68/100, combining SEO, performance, security, and accessibility.

substackcdn.com

Error - Substack

Last scanned Jul 21, 2026, 12:33 PM · 1 view

Overall score

Fair

Top issues to fix

13 issues found · 5 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 meta description
SEO
Add a ~150-character meta description to control your search-result snippet and lift click-through rate.
No H1 heading found
SEO
Add exactly one H1 describing the page's main topic — it anchors the document outline for search engines and screen readers.
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.

+7 more issues — details in the sections below.

Summary

This website is hosted on AWS. SEO is fair (55/100) and accessibility is fair (50/100). Security scores fair (65/100) and performance excellent (100/100). Top issue: Missing meta description.

SEO

6 issue(s) found

100

Performance

473 ms

Security

HTTPS & header checks

Accessibility

3 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.

Meta tags

Title: Error - Substack
Description
Canonical
Language
Charset: utf-8
Viewport: width=device-width, initial-scale=1, maximum-scale=1, user-scalable=0
Robots meta
Manifest

Technologies

Detected frameworks, languages, and tools.

No technologies detected.

Hosting & CDN

Hosting provider: AWS
CDN provider: CloudFront
IP address: 18.66.57.95
ASN: AS16509 (AMAZON-02 - Amazon.com, Inc., US)

DNS records

Type	Value
A	18.66.57.95 18.66.57.8 18.66.57.117 18.66.57.24
AAAA	2600:9000:2379:ae00:4:b4b9:d3c0:93a1 2600:9000:2379:9a00:4:b4b9:d3c0:93a1 2600:9000:2379:7400:4:b4b9:d3c0:93a1 2600:9000:2379:9600:4:b4b9:d3c0:93a1 2600:9000:2379:5600:4:b4b9:d3c0:93a1 2600:9000:2379:2c00:4:b4b9:d3c0:93a1 2600:9000:2379:c400:4:b4b9:d3c0:93a1 2600:9000:2379:8c00:4:b4b9:d3c0:93a1
MX	—
TXT	google-site-verification=tz2v--AUiNuSpVyU440dvghhnTS9kVnvhIWn69muzgs
NS	ns-946.awsdns-54.net ns-1936.awsdns-50.co.uk ns-98.awsdns-12.com ns-1445.awsdns-52.org
CAA	—
CNAME	—
IPv6 support	Yes

TLS / SSL certificate

Version: TLS 1.3
Issuer: Amazon
Subject: substackcdn.com
Valid from: Dec 14, 2025
Valid to: Jan 12, 2027
Days until expiry: 175
SAN domains: substackcdn.com

Security headers

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

Compression: none · 0 cookie(s) observed

Content & assets

Headings

H1 0 · H2 0 · H3 0

Links

0 internal · 1 external · 1 broken

Images

1 total · 1 missing alt

Scripts / Styles

0 scripts · 0 stylesheets

JS / CSS size

0 B · 771 B

Page size

5.5 KB

Robots.txt & Sitemap

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

SEO issues

Missing meta description
Missing canonical link
No H1 heading found
No structured data (JSON-LD) found
Missing OpenGraph tags
sitemap.xml not found

Scan details

Requested URL: https://substackcdn.com
Final URL: https://substackcdn.com
HTTP status: 403
HTTP version: HTTP/2
Response time: 473 ms
HTML size: 5.5 KB
Redirect chain: https://substackcdn.com

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