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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
98
GRADE
A+
FIX
1
REVIEW
1
PASS
7
INFO
0
Probed from Madrid, Spain
302 Found
Checks
9
7 PASS 1 REVIEW 1 FIX
D
CDN & Delivery
Action
No CDN detected
FIX
No CDN detected
Warning::
No CDN detected
A CDN can significantly improve load times for users around the world by caching content at edge nodes closer to them.
No CDN detected

Consider using a CDN to improve global delivery speed and reduce origin load.

B
TLS Certificate Expiry & Recommendations
317 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

317
days left
0d 30d 60d 90d+

Recommended actions

  • Add includeSubDomains to the HSTS directive
  • Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
  • Enable DNSSEC on your domain for DNS spoofing protection
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A+
DNS Records
3 A records, 38 ms lookup
PASS
3 A records, 38 ms lookup
Info::
Resolves to 3 IPv4 address(es)
Got: 54.163.203.83, 44.193.165.2, 44.206.204.180
Info::
Has 3 IPv6 (AAAA) record(s)
Got: 2600:1f18:2148:bc02:6c3c:658f:8bcf:4bf7, 2600:1f18:2148:bc00:bb41:6176:22ce:6757, 2600:1f18:2148:bc01:b693:b462:3ebf:eff0
Info::
4 nameserver(s) configured
Got: ns-513.awsdns-00.net, ns-421.awsdns-52.com, ns-1827.awsdns-36.co.uk, ns-1168.awsdns-18.org
Info::
6 mail exchanger(s) configured
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
SPF record present in TXT
Info::
DNS resolution time: 38 ms
Got: 38 ms
A54.163.203.83, 44.193.165.2, 44.206.204.180
AAAA2600:1f18:2148:bc02:6c3c:658f:8bcf:4bf7, 2600:1f18:2148:bc00:bb41:6176:22ce:6757, 2600:1f18:2148:bc01:b693:b462:3ebf:eff0
CNAME—
NSns-513.awsdns-00.net, ns-421.awsdns-52.com, ns-1827.awsdns-36.co.uk, ns-1168.awsdns-18.org
MX
10 aspmx.l.google.com
20 alt1.aspmx.l.google.com
30 aspmx5.googlemail.com
30 aspmx2.googlemail.com
30 aspmx3.googlemail.com
30 aspmx4.googlemail.com
TXT
994564986-4236403
detectify-verification=87a64c3bf3301354588d90672bd1b74e
google-site-verification=v2_0BdJWKUR2kM7Ysv_QB9LhCqd2Xn6QCZiInuaRwFc
google-site-verification=cusX3h3wUlq3D6vk24INmIXpuJdQ46-uKjIAM9Of8Lo
SPF v=spf1 include:mailgun.org -all
CAALookup not available with standard resolver
Resolved in 38 ms

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

A
Redirect Chain
1 redirect(s), 317 ms total
PASS
1 redirect(s), 317 ms total
Info::
Single redirect
Got: https://docker.io → https://www.docker.com/ (302)
Info::
WWW normalization redirect
Info::
Uses 302 (temporary) redirect
If permanent, use 301 instead.
Got: https://docker.io
Info::
Cross-domain redirect detected

https://docker.io

293 ms · HTTP/1.1

302

https://www.docker.com/

24 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://docker.io302293 msHTTP/1.1
2https://www.docker.com/20024 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

If permanent, use 301 instead.

Why this matters

302 (Found) is for genuinely temporary redirects — if this redirect is permanent, switch to 301 to preserve SEO equity.

Learn more ▾

Search engines treat 302 as temporary, keeping the original URL indexed and not transferring full link equity to the destination. Use 301 (Moved Permanently) for permanent redirects (HTTP→HTTPS, www-vs-non-www, URL restructures).

Source: Google Search Central

A+
IPv6 Readiness
IPv6 reachable (98 ms)
PASS
IPv6 reachable (98 ms)
Info::
IPv6 is configured and reachable at 2600:1f18:2148:bc02:6c3c:658f:8bcf:4bf7, 2600:1f18:2148:bc00:bb41:6176:22ce:6757, 2600:1f18:2148:bc01:b693:b462:3ebf:eff0
Got: 98 ms connect
IPv6 Ready
AAAA Records 2600:1f18:2148:bc02:6c3c:658f:8bcf:4bf7, 2600:1f18:2148:bc00:bb41:6176:22ce:6757, 2600:1f18:2148:bc01:b693:b462:3ebf:eff0 Connection Reachable (98 ms)
A+
Crawlability
robots.txt present, sitemap with 15 URLs
PASS
robots.txt present, sitemap with 15 URLs
Info::
robots.txt is present
Got: 1033 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 15 entries
Info::
Sitemap index with 15 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 1033 B Sitemaps referenced 2 User-agents * Blocking No — crawling allowed
User-agent: *
Allow: /wp-admin/admin-ajax.php
Disallow: /wp-admin/
Disallow: /pricing/contact-sales/bss-cc-thankyou/
Disallow: /pricing/contact-sales/bss-thankyou/
Disallow: /company/contact-thank-you/
Disallow: /thank-you-subscribing-docker-weekly/
Disallow: /pricing/contact-sales2/
Disallow: /cdn-cgi/
Disallow: /static/
Disallow: /c/
Disallow: /p/
Disallow: /products/telepresence-for-docker/thank-you/
Disallow: /style-guide/
Disallow: /search/

Allow: /ja-jp/wp-admin/admin-ajax.php
Disallow: /ja-jp/wp-admin/
Disallow: /ja-jp/pricing/contact-sales/bss-cc-thankyou/
Disallow: /ja-jp/pricing/contact-sales/bss-thankyou/
Disallow: /ja-jp/company/contact-thank-you/
Disallow: /ja-jp/thank-you-subscribing-docker-weekly/
Disallow: /ja-jp/pricing/contact-sales2/
Disallow: /ja-jp/cdn-cgi/
Disallow: /ja-jp/static/
Disallow: /ja-jp/c/
Disallow: /ja-jp/products/telepresence-for-docker/thank-you/
Disallow: /ja-jp/style-guide/


Sitemap: https://www.docker.com/sitemap_index.xml
Sitemap: https://www.docker.com/ja-jp/sitemap_index.xml
sitemap.xml 200 OK
Type Sitemap Index URLs 15 entries Valid XML Yes
Child Sitemaps:
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: non-www)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

302https://www.docker.io/
200https://docker.io/

Preferred variant: non-www

HTTP → HTTPS

301http://docker.io/ → https://docker.io:443/

Consistent

A+
Domain Intelligence
docker.io — via Gandi SAS, 13 years, 6 months old
PASS
docker.io — via Gandi SAS, 13 years, 6 months old
Info::
Domain registered until Dec 17, 2026 (8 months remaining)
Info::
Registrar: Gandi SAS
Info::
Registrar lock is enabled
Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.
Domain expiry

185 days

December 17, 2026

SSL certificate

317 days

Issued by Amazon

Domain age

13 years, 6 months

Registered December 17, 2012

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2600:1f18:2148:bc02:6c3c:658f:8bcf:4bf7

Registrar

Gandi SAS

Locked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar Gandi SAS
Created December 17, 2012 (13 years, 6 months ago)
Expires December 17, 2026 (8 months)
Last Updated November 23, 2025
Name Servers ns-1168.awsdns-18.org, ns-421.awsdns-52.com, ns-1827.awsdns-36.co.uk, ns-513.awsdns-00.net
Registrant Docker Inc.
Hosting
IP Address 2600:1f18:2148:bc02:6c3c:658f:8bcf:4bf7
Data source: whois (1.0s)

Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.

Why this matters

Registrar lock (clientTransferProhibited et al.) prevents unauthorized domain transfers — strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

A+
HTTP Probe Timing
Total 318 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
21 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
98 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
100 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
318 ms
Total Time Total request time from DNS lookup through full response.
318 ms

Connection waterfall

DNS Lookup 21 ms TCP Connect 98 ms TLS Handshake 100 ms Server Processing 99 ms Content Transfer 0 ms
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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