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https://masterclass.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
98
GRADE
A+
FIX
0
REVIEW
2
PASS
7
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
7 PASS 2 REVIEW
B
TLS Certificate Expiry & Recommendations
50 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

50
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • 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
B
CDN & Delivery
Cloudflare
REVIEW
Cloudflare
Info::
Site is served via Cloudflare CDN (edge: CDG)
Got: cf-ray: 9f00167e1a6b6f84-CDG
CDN Detected: Cloudflare
Provider Cloudflare Evidence cf-ray: 9f00167e1a6b6f84-CDG
A+
DNS Records
2 A records, 93 ms lookup
PASS
2 A records, 93 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 104.17.11.109, 104.17.12.109
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2606:4700::6811:b6d, 2606:4700::6811:c6d
Info::
2 nameserver(s) configured
Got: lara.ns.cloudflare.com, elmo.ns.cloudflare.com
Info::
5 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: 93 ms
Got: 93 ms
A104.17.11.109, 104.17.12.109
AAAA2606:4700::6811:b6d, 2606:4700::6811:c6d
CNAME—
NSlara.ns.cloudflare.com, elmo.ns.cloudflare.com
MX
1 aspmx.l.google.com
5 alt2.aspmx.l.google.com
5 alt1.aspmx.l.google.com
10 alt3.aspmx.l.google.com
10 alt4.aspmx.l.google.com
TXT
stripe-verification=a724da2600b32898d16a622d440ffe5df365aede0ea0085dac363d14e7d5...
zapier-domain-verification-challenge=157c535c-55e3-47db-afae-588cd71db34b
adobe-idp-site-verification=8cecf303de49e79f3bdba851120976cc135e573af7e1415614ad...
h1-domain-verification=P8nffKmUSEtYWiazMh7ywjrjwYuWCV2BNT4twJXMhygtq8aq
segment-site-verification=uqDqIFigNS4vDmAD8EmAGhRsRpIVpvX4
atlassian-domain-verification=fsLNVMHXTinbduijD9qeWWVOBbtM0ktMigExcpz84eXkqnvQWE...
google-site-verification=n1Yz2XSiiz2Zq-fqb_3r0Vxu6nu4aJYocC-yApmymZo
onetrust-domain-verification=402a912e5f60472faac5ae0be70f2ac0
google-site-verification=iQxG-q_4dr0FA3Ao1DRrgLQjWqmL52fGQwUQxBEacQw
cursor-domain-verification-gcpwkw=M0JNzcmFlXXDV3hxBDtgwzC8U
stripe-verification=BAC58CD27A726CB57A22A94CF194159DC8AEC807D3C552A42D196543806C...
jamf-site-verification=-EgzC23s3-FEy67wN_mmkA
gamma-domain-verification-5h4yh2=nNmT1WskPGUEevoEumWLfuiQQ
segment-site-verification=G8EClOzpb9DOxF39ihbSmVtb2j6hv5vz
openai-domain-verification=dv-GcY4FzLCwaYMyMTHJyhXx0F0
elevenlabs=uI1io7p5QnHLXBO4aIDSPbT1cilewVmgyBHbIv5yP3A
docusign=6a55ec11-02b4-4add-89e3-635c4c845c02
jetbrains-domain-verification=cmohn0y9vdknqw3qaisdk6sn7
google-site-verification=eKv2UoTFDkYJ7Oj3zLj0cMpKYWTiIg90xNLRih9GFVQ
ZOOM_verify_MPUyRtnpQ-KCjAo8dCLHtA
google-site-verification=ZLRIGV-xmlMAsluAM6Q0sXrYlH9i_lNOPure0L5-FRY
MS=ms40464053
google-site-verification=HBtTedJJzGqpI0XzHnITC3kJW_kQizrx6qj-pJsBYpk
facebook-domain-verification=vko59lt5tiv3e15nlz3fz0ndzaa48k
google-site-verification=82VH4G93yO_5Q3pQCMlhCigfy6YiJW9VB2BgLv1acNU
stripe-verification=05be685f2aa766fd02db629e200de6599f96a26ac878f011ca07f4e460ea...
jumpdesktop=7ffc143dc6e1d1c8ce3cc46d41f514753764c58441fddc7e1745499243df
figma-domain-verification=c03ba85be58bb787cf163df010d8a8f566914bdca30d4a8b4daa45...
serval-domain-verification-dgcjt0=dVNwJAK7PsxoQPKJ54kzoTO8Q
opus-clip-domain-verification-zemts8=ojPEL6WKEqGIE4oKs1MGcmXsq
apple-domain-verification=Dwh77ggSYSJLv0sV
dropbox-domain-verification=qzcecejb36yn
stripe-verification=f4598fc28f5441e04a5f78cd69c1df5e2679418ccd8659c94a62348c027e...
teamviewer-sso-verification=63cefa94ee3247beb570154f96dac6f4
atlassian-domain-verification=z8jowpBlkVJiTOqh0KMVPyRiJPZS62sQS/xQk08yGwdNQZ3mxJ...
anthropic-domain-verification-09srn7=YDOqYXJCGJNNLdEfNFn4Bv2K6
pardot923373=eb51071010d88eac96762e419f98e03d8428bd9cbfc2748b1286e18b33fcf0b1
google-site-verification=UicQjDg7QYyoskEBnAx7DNiYZq2bNIovIdmTY8NEXkE
airtable-verification=2e81434c48c7f1f5f14e32e768aac1f1
00d5y000002tzbcuac
SPF v=spf1 ip4:198.245.81.0/24 ip4:136.147.176.0/24 ip4:13.111.0.0/16 ip4:136.147.18...
CAALookup not available with standard resolver
Resolved in 93 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), 154 ms total
PASS
1 redirect(s), 154 ms total
Info::
Single redirect
Got: https://masterclass.com → https://www.masterclass.com/ (301)
Info::
WWW normalization redirect

https://masterclass.com

61 ms · HTTP/1.1

301

https://www.masterclass.com/

94 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://masterclass.com30161 msHTTP/1.1cloudflare
2https://www.masterclass.com/40394 msHTTP/1.1cloudflare

See the visual redirect chain in the HTTP Probe tab →

A+
IPv6 Readiness
IPv6 reachable (17 ms)
PASS
IPv6 reachable (17 ms)
Info::
IPv6 is configured and reachable at 2606:4700::6811:b6d, 2606:4700::6811:c6d
Got: 17 ms connect
IPv6 Ready
AAAA Records 2606:4700::6811:b6d, 2606:4700::6811:c6d Connection Reachable (17 ms)
A+
Crawlability
robots.txt present, sitemap with 218 URLs
PASS
robots.txt present, sitemap with 218 URLs
Info::
robots.txt is present
Got: 782 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 218 entries
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 782 B Sitemaps referenced 5 User-agents GPTBot, CCBot, ClaudeBot, Google-Extended, * Blocking No — crawling allowed
# *
User-agent: *
Allow: /
Disallow: /guest-pass/*
Disallow: /free-trial
Disallow: /exclusive-guest-pass
Disallow: /auth/reset-password/finish/*
Disallow: /classes/*.txt
Disallow: /classes/*.html
Disallow: /classes/*.amp
Disallow: /classes/*.In
Disallow: /*US_CENSUS_NAME*

# GPTBot
User-agent: GPTBot
Allow: /

# CCBot
User-agent: CCBot
Allow: /

# ClaudeBot
User-agent: ClaudeBot
Allow: /

# Google-Extended
User-agent: Google-Extended
Allow: /

# Host
Host: https://www.masterclass.com/

# Sitemaps
Sitemap: https://www.masterclass.com/sitemap.xml
Sitemap: https://www.masterclass.com/sitemap-classes.xml
Sitemap: https://www.masterclass.com/sitemap-lessons.xml
Sitemap: https://www.masterclass.com/sitemap-articles.xml
Sitemap: https://www.masterclass.com/executive/sitemap.xml
sitemap.xml 200 OK
Type URL Set URLs 218 entries Valid XML Yes
Sample URLs:
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

403https://www.masterclass.com/
200https://masterclass.com/

HTTP → HTTPS

301http://masterclass.com/ → https://masterclass.com/

Consistent

A+
Domain Intelligence
masterclass.com — via GoDaddy.com, LLC, 31 years old
PASS
masterclass.com — via GoDaddy.com, LLC, 31 years old
Info::
Domain registered until Sep 15, 2029 (3 years, 5 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.
Domain expiry

1154 days

September 15, 2029

SSL certificate

50 days

Issued by Google Trust Services

Domain age

31 years

Registered September 16, 1995

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2606:4700::6811:b6d

Registrar

GoDaddy.com, LLC

Unlocked 2 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 September 16, 1995 (31 years ago)
Expires September 15, 2029 (3 years, 5 months)
Last Updated September 6, 2024
Name Servers elmo.ns.cloudflare.com, lara.ns.cloudflare.com
DNSSEC Not enabled
Hosting
IP Address 2606:4700::6811:b6d
Data source: rdap (0.1s)

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 100 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
38 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.
23 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
101 ms
Total Time Total request time from DNS lookup through full response.
101 ms

Connection waterfall

DNS Lookup 38 ms TCP Connect 16 ms TLS Handshake 23 ms Server Processing 23 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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