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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
87
GRADE
B
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
6 PASS 3 REVIEW
C
IPv6 Readiness
Action
No IPv6 support
REVIEW
No IPv6 support
Info::
No IPv6 (AAAA) records found
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No IPv6 Support
About 40% of internet users have IPv6. Consider adding AAAA records.

IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.

Why this matters

No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.

Source: Google IPv6 stats

B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Critical::
Both www and non-www versions serve content
Got: Both variants return 200 Expected: One variant 301-redirects to the other
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.coursera.org/
200https://coursera.org/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://coursera.org/ → https://coursera.org/

Consistent

B
TLS Certificate Expiry & Recommendations
174 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

174
days left
0d 30d 60d 90d+

Recommended actions

  • Submit your domain to hstspreload.org to be added to the Chrome preload list
  • 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
4 A records, 103 ms lookup
PASS
4 A records, 103 ms lookup
Info::
Resolves to 4 IPv4 address(es)
Got: 13.227.231.38, 13.227.231.36, 13.227.231.106, 13.227.231.90
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-258.awsdns-32.com, ns-688.awsdns-22.net, ns-1590.awsdns-06.co.uk, ns-1481.awsdns-57.org
Info::
7 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: 103 ms
Got: 103 ms
A13.227.231.38, 13.227.231.36, 13.227.231.106, 13.227.231.90
AAAA—
CNAME—
NSns-258.awsdns-32.com, ns-688.awsdns-22.net, ns-1590.awsdns-06.co.uk, ns-1481.awsdns-57.org
MX
10 aspmx.l.google.com
20 alt2.aspmx.l.google.com
20 alt1.aspmx.l.google.com
30 aspmx3.googlemail.com
30 aspmx5.googlemail.com
30 aspmx2.googlemail.com
30 aspmx4.googlemail.com
TXT
onetrust-domain-verification=bc353cda9f49402e8b2ac8a3b3e86286
cisco-ci-domain-verification=5b418d2526e560d4ec96988886c86e7930c6936b68215183295...
openai-domain-verification=dv-ykQklEbL6szace8vG1l7ejkQ
hubspot-domain-verification=ZTM1ZDk4NGEtNWU5Ny00NDJiLWIwNTQtZTA1NGJhZmU3MzZh
google-site-verification=BbSjFsQN-aTkQDOiar6q3O4fPzSlgepoOdM3fMuCXFA
google-site-verification=fFsckLsIOub_171zkeWLBQ72SvjwGSPsz209wwTtmX4
MS=ms91657421
jamf-site-verification=AmVhIhwqDzkoVxg_B0K81w
canva-site-verification=m3eGQL4tz88BqXJO92JRpw
google-site-verification=tbpsWy5oBEvo-Kod36Lqsb3qRK0h_divcCGAeUdVZlk
google-site-verification=61uiBFuqY-MYJHWt_8qbU00Rsn7Nq_njU5eMUG0NlrY
SPF v=spf1 include:sendgrid.net ip4:24.6.102.21 ip4:50.16.53.44 include:_spf.google....
yandex-verification: 7472d03e746e191a
cursor-domain-verification-kg2va5=P61NAJ77jH4Kuavd9jaD3I4Bw
stripe-verification=0f6967e13ea84d76953d1c3f2dc9eb80e82f090fff99161cd2fa957f55a7...
paloaltonetworks-site-verification=3d8b8eeec8974a6c2b181f7decddc8a96d9cbdcb8f39e...
google-site-verification=H2oN7Mv4QCzOClwXz1j30f-4544byEDxyEk0o3eluE0
miro-verification=d5e807f40d602cde4051496eaaa95234e158ada0
stripe-verification=95449f6ae01b02ef7f65b59ee2f3ed14bac52c49aaa1519e57b864b70bae...
docusign=05d7ee1b-a029-4b94-912a-25bb3c4a2bed
jamf-site-verification=Q2xELHJlL4PRcETKdUHldQ
facebook-domain-verification=46dep9ql4m6it0wahwkhiou7xit57h
google-site-verification=UGpuPtZLCcMKFmgAeN4q6EbvxJn56A8Jz0sgW3yVKmA
apple-domain-verification=8gxy28dzSlSOYkUI
atlassian-domain-verification=pwnyCbGEmC6E08lYJGO/SYkQvbjFS+OXy03eVMG75U52Edj0vb...
BthfBdp8W7Bqmm87eNGy
docker-verification=6792a290-383f-4d78-9f9b-71f46df7b6b2
zoom-domain-verification=6fb6c268-238e-477b-ba40-2f0164695cd7
elevenlabs=iuq-HrTSPpSbgooOeznbfY9bR-awTAYggzjFxD0Q6Rw
stripe-verification=34fd6b74183c244d59d572c162e5b77fe6eed5e5205296151f49dda7b686...
atlassian-domain-verification=OwoxnU5JeeEeNB3PXqTmPOsZNFUYTd05tar4PX8ZNNjps+mMWt...
spf2.0/pra include:amazonses.com include:sendgrid.net include:_spf.google.com in...
google-site-verification=nLfEbuY6OaO0lfas7ywHqpPnOMnobNONSJ0hnbJO9co
google-site-verification=PDgfi1HUgagq2NZOh86B3PpGnjDyNXdUr9iyWzDjONM
rzp-site-verification=0e1f055c2e81430150efedded50e7992
google-site-verification=l-IugqqOHDGlHpUHfv3e6z8J1koLgfGSem04lqBA_B8
google-site-verification=874wxzrE4FAJO81XTCXyH6WYnWZAMdlbMRXI3lfI0bw
anthropic-domain-verification-r913z0=qHfIpP1D8b5nWxj2rpstnqRZ1
376174617-10056694
CAALookup not available with standard resolver
Resolved in 103 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), 542 ms total
PASS
1 redirect(s), 542 ms total
Info::
Single redirect
Got: https://coursera.org → https://www.coursera.org/ (301)
Info::
WWW normalization redirect
Info::
Redirect overhead: 542 ms total
Got: 542 ms

https://coursera.org

141 ms · HTTP/1.1

301

https://www.coursera.org/

401 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://coursera.org301141 msHTTP/1.1
2https://www.coursera.org/200401 msHTTP/1.1envoy

See the visual redirect chain in the HTTP Probe tab →

A+
Crawlability
robots.txt present, sitemap with 18 URLs
PASS
robots.txt present, sitemap with 18 URLs
Info::
robots.txt is present
Got: 1291 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 18 entries
Info::
Sitemap index with 18 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 1291 B Sitemaps referenced 1 User-agents Twitterbot, ChatGPT-User, CCBot, Google-Extended, LinkedInBot, meta-externalagent, OAI-SearchBot, *, GPTBot, ClaudeBot, MistralAI-User, PerplexityBot Blocking No — crawling allowed
User-agent: *
Allow: /api/utilities/v1/imageproxy
Disallow: /maestro/api/
Disallow: /api/
Disallow: /maestro/
Disallow: /ui/
Disallow: /signature/voucher/
Disallow: /account/
Disallow: /acclaimbadge/
Disallow: /voucher/
Disallow: /search
Disallow: /ent-website/
Disallow: /learn-perf/
Disallow: /specializations-perf/
Disallow: /professional-certificates-perf/
Disallow: /learn-noperf/
Disallow: /specializations-noperf/
Disallow: /professional-certificates-noperf/
Disallow: /business/xmlrpc.php
Disallow: /business/wp-content/uploads/ 
Disallow: /business/search
Disallow: /business/teams/search
Sitemap: https://www.coursera.org/sitemap.xml



User-agent: CCBot
Disallow: /lecture/

User-agent: GPTBot
Disallow: /lecture/

User-agent: ClaudeBot
Disallow: /lecture/

User-agent: MistralAI-User
Disallow: /lecture/

User-agent: Google-Extended
Disallow: /lecture/

User-agent: PerplexityBot
Disallow: /lecture/

User-agent: LinkedInBot
Allow: /account/accomplishments/

User-agent: Twitterbot
Allow: /account/accomplishments/

User-agent: meta-externalagent
Disallow: /

User-agent: OAI-SearchBot
Allow: /
Disallow: /programs/
Disallow: /account/
Disallow: /api/
Disallow: /search

User-agent: ChatGPT-User
Allow: /
Disallow: /programs/
Disallow: /account/
Disallow: /api/
Disallow: /search
sitemap.xml 200 OK
Type Sitemap Index URLs 18 entries Valid XML Yes
Child Sitemaps:
A+
Domain Intelligence
coursera.org — via GoDaddy.com, LLC, 14 years, 5 months old, hosted on AWS
PASS
coursera.org — via GoDaddy.com, LLC, 14 years, 5 months old, hosted on AWS
Info::
Domain registered until Jan 12, 2027 (9 months remaining)
Info::
DNSSEC is not enabled
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Info::
Registrar: GoDaddy.com, LLC
Warning::
Registrar lock is NOT enabled
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Info::
Hosting: AWS
Got: AS16509
Domain expiry

148 days

January 12, 2027

SSL certificate

174 days

Issued by Amazon

Domain age

14 years, 5 months

Registered January 12, 2012

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

13.227.231.90

Registrar

GoDaddy.com, LLC

Unlocked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Enable DNSSEC to protect visitors from DNS spoofing
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar GoDaddy.com, LLC
Created January 12, 2012 (14 years, 5 months ago)
Expires January 12, 2027 (9 months)
Last Updated February 26, 2026
Name Servers ns-1481.awsdns-57.org, ns-1590.awsdns-06.co.uk, ns-258.awsdns-32.com, ns-688.awsdns-22.net
DNSSEC Not enabled
Hosting
IP Address 13.227.231.90
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.8s)

DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.

Why this matters

Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.

Learn more ▾

DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.

Source: ICANN / RFC 4033

The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.

Why this matters

Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.

Learn more ▾

Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

A+
HTTP Probe Timing
Total 168 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
29 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
16 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
18 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
168 ms
Total Time Total request time from DNS lookup through full response.
168 ms

Connection waterfall

DNS Lookup 29 ms TCP Connect 16 ms TLS Handshake 18 ms Server Processing 105 ms Content Transfer 0 ms
A
CDN & Delivery
AWS CloudFront (Miss from cloudfront)
PASS
AWS CloudFront (Miss from cloudfront)
Info::
Site is served via AWS CloudFront CDN (edge: CDG50-P5)
Got: x-amz-cf-id: 5cyuvs87dUBqVW7-RiuO0LRETU8X0_bH_hG5DlfE4vlehqQT2XzRMA==
Info::
CDN cache status: Miss from cloudfront
CDN Detected: AWS CloudFront
Provider AWS CloudFront Cache Status Miss from cloudfront Evidence x-amz-cf-id: 5cyuvs87dUBqVW7-RiuO0LRETU8X0_bH_hG5DlfE4vlehqQT2XzRMA==
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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