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https://stumbleupon.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
85
GRADE
B
FIX
1
REVIEW
4
PASS
4
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
4 PASS 4 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.

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
Crawlability
no robots.txt, no sitemap
REVIEW
no robots.txt, no sitemap
Info::
No robots.txt found
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.

robots.txt is optional but recommended. It tells search engine crawlers which pages to index.

Why this matters

No robots.txt — crawlers fetch /robots.txt and get 404; not breaking but means default crawl behavior with no directives or sitemap reference.

Learn more

A minimal robots.txt with `User-agent: * / Allow: / / Sitemap: https://example.com/sitemap.xml` covers the basics. Without it, crawlers behave fine but lose the sitemap signal and can't be selectively blocked from crawl-traps.

Source: robotstxt.org

A sitemap helps search engines discover and index your pages more efficiently.

Why this matters

No sitemap.xml — Google relies on crawl-graph discovery alone, slowing indexing of deep or fresh URLs.

Learn more

A sitemap accelerates Google's discovery of new and updated content. Most CMSes auto-generate one; static-site frameworks need a build-step plugin. Reference it from robots.txt and submit in Search Console to confirm Google can fetch it.

Source: sitemaps.org / Google Search Central

robots.txt No robots.txt found

No robots.txt found

This is fine for most sites — a missing robots.txt allows all crawling by default.

sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

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.stumbleupon.com/
200https://stumbleupon.com/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://stumbleupon.com/ https://stumbleupon.com:443/

Consistent

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

Certificate validity

66
days left
0d 30d 60d 90d+

Recommended actions

  • Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
  • 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
A+
DNS Records
3 A records, 29 ms lookup
PASS
3 A records, 29 ms lookup
Info::
Resolves to 3 IPv4 address(es)
Got: 54.235.101.130, 35.173.166.98, 3.229.150.138
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-1116.awsdns-11.org, ns-521.awsdns-01.net, ns-358.awsdns-44.com, ns-1950.awsdns-51.co.uk
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: 29 ms
Got: 29 ms
A54.235.101.130, 35.173.166.98, 3.229.150.138
AAAA
CNAME
NSns-1116.awsdns-11.org, ns-521.awsdns-01.net, ns-358.awsdns-44.com, ns-1950.awsdns-51.co.uk
MX
1 aspmx.l.google.com
5 alt1.aspmx.l.google.com
5 alt2.aspmx.l.google.com
10 alt3.aspmx.l.google.com
10 alt4.aspmx.l.google.com
TXT
SPF v=spf1 include:_spf.google.com ~all
CAALookup not available with standard resolver
Resolved in 29 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
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://stumbleupon.com

https://stumbleupon.com

418 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://stumbleupon.com200418 msHTTP/1.1
A+
Domain Intelligence
stumbleupon.com — via MarkMonitor Inc., 24 years, 9 months old, hosted on AWS
PASS
stumbleupon.com — via MarkMonitor Inc., 24 years, 9 months old, hosted on AWS
Info::
Domain registered until Nov 6, 2027 (1 years, 6 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: MarkMonitor Inc.
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: AS14618
Domain expiry

479 days

November 6, 2027

SSL certificate

66 days

Issued by Amazon

Domain age

24 years, 9 months

Registered November 6, 2001

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS14618

3.229.150.138

Registrar

MarkMonitor Inc.

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 MarkMonitor Inc.
Created November 6, 2001 (24 years, 9 months ago)
Expires November 6, 2027 (1 years, 6 months)
Last Updated October 5, 2025
Name Servers ns-1116.awsdns-11.org, ns-1950.awsdns-51.co.uk, ns-358.awsdns-44.com, ns-521.awsdns-01.net
DNSSEC Not enabled
Hosting
IP Address 3.229.150.138
ASN AS14618 (AMAZON-AES - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.3s)

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 420 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
28 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
95 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
194 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
420 ms
Total Time Total request time from DNS lookup through full response.
420 ms

Connection waterfall

DNS Lookup 28 ms TCP Connect 95 ms TLS Handshake 194 ms Server Processing 103 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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