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https://khanacademy.org

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
80
GRADE
B
FIX
0
REVIEW
5
PASS
4
INFO
0
Probed from Madrid, Spain
308 Permanent Redirect
Checks
9
4 PASS 5 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

C
Crawlability
Action
robots.txt present, sitemap with 0 URLs
REVIEW
robots.txt present, sitemap with 0 URLs
Info::
robots.txt is present
Got: 3038 bytes
Info::
sitemap.xml is present
Warning::
sitemap.xml contains invalid XML
Search engines may not be able to parse the sitemap. Fix XML validation errors.
Warning::
sitemap.xml is empty — no URLs found
An empty sitemap provides no value. Add <url> entries for your pages.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Search engines may not be able to parse the sitemap. Fix XML validation errors.

Why this matters

An unparseable sitemap is silently ignored by Google — the URLs it advertises are never queued for crawl.

Learn more

Google's sitemap parser is strict about XML validity. A single unescaped `&` or unclosed tag invalidates the whole file. Run your sitemap through a validator (Search Console's Sitemaps report flags it) and fix the offending entry. Most generators escape correctly; mistakes usually come from manually-written entries.

Source: sitemaps.org / Google Search Central

An empty sitemap provides no value. Add <url> entries for your pages.

Why this matters

An empty sitemap signals 'no content to index' to Google — actively harmful versus having no sitemap at all.

Learn more

Google compares URLs in the sitemap against URLs it has crawled. An empty sitemap on a site with thousands of pages signals abandonment. Either populate it correctly (most CMSes auto-generate) or delete the file and let Google crawl normally.

Source: Google Search Central / sitemaps.org

Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

Why this matters

robots.txt omits Sitemap: directive — crawlers must fetch /sitemap.xml by convention; reliable but missing the explicit hint.

Source: sitemaps.org

robots.txt 200 OK
Size 3038 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta
      http-equiv="Content-Security-Policy"
      content="default-src 'self'; img-src 'self' data:; media-src 'self' data:; object-src 'none'; style-src 'self' 'sha256-o4vzfmmUENEg4chMjjRP9EuW9ucGnGIGVdbl8d0SHQQ='; script-src 'self' 'sha256-a9bHdQGvRzDwDVzx8m+Rzw+0FHZad8L0zjtBwkxOIz4=';"
    />
    <link
      href="/_fs-ch-1T1wmsGaOgGaSxcX/assets/inter-var.woff2"
      rel="preload"
      as="font"
      type="font/woff2"
      crossorigin
    />
    <link href="/_fs-ch-1T1wmsGaOgGaSxcX/assets/styles.css" rel="stylesheet" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>Client Challenge</title>
    <style>
      #loading-error {
        font-size: 16px;
        font-family: 'Inter', sans-serif;
        margin-top: 10px;
        margin-left: 10px;
        display: none;
      }
    </style>
  </head>
  <body>
    <noscript>
      <div class="noscript-container">
        <div class="noscript-content">
          <img
            src="/_fs-ch-1T1wmsGaOgGaSxcX/assets/errorIcon.svg"
            alt=""
            role="presentation"
            class="error-icon"
          />
          <span class="noscript-span"
            >JavaScript is disabled in your browser.</span
          >
          <p>Please enable JavaScript to proceed.</p>
        </div>
      </div>
    </noscript>
    <div id="loading-error" role="alert" aria-live="polite">
      A required part of this site couldn’t load. This may be due to a browser
      extension, network issues, or browser settings. Please check your
      connection, disable any ad blockers, or try using a different browser.
    </div>
    <script>
      function loadScript(src) {
        return new Promise((resolve, reject) => {
          const script = document.createElement('script');
          script.onload = resolve;
          script.onerror = (event) => {
            console.error('Script load error event:', event);
            document.getElementById('loading-error').style.display = 'block';
            reject(
              new Error(
                `Failed to load script: ${src}, Please contact the service administrator.`
              )
            );
          };
          script.src = src;
          document.body.appendChild(script);
        });
      }

      loadScript('/_fs-ch-1T1wmsGaOgGaSxcX/errors.js')
        .then(() => {
          const script = document.createElement('script');
          script.src = '/_fs-ch-1T1wmsGaOgGaSxcX/script.js?reload=true';
          script.onerror = (event) => {
            console.error('Script load error event:', event);
            const errorMsg = new Error(
              `Failed to load script: ${script.src}. Please contact the service administrator.`
            );
            console.error(errorMsg);
            handleScriptError();
          };
          document.body.appendChild(script);
        })
        .catch((error) => {
          console.error(error);
        });
    </script>
  </body>
</html>

sitemap.xml 200 OK
Type URL Set URLs 0 entries Valid XML No
C
URL Variants
Action
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
Warning::
HTTP→HTTPS redirect uses 302 instead of 301
Got: 302 temporary redirect Expected: 301 permanent redirect

www / non-www

200https://www.khanacademy.org/
200https://khanacademy.org/

Inconsistent — duplicate content risk

HTTP → HTTPS

308http://khanacademy.org/ https://www.khanacademy.org/

Use 301 (permanent) instead of 302 (temporary)

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

Certificate validity

239
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
AWS CloudFront (FunctionGeneratedResponse from cloudfront)
REVIEW
AWS CloudFront (FunctionGeneratedResponse from cloudfront)
Info::
Site is served via AWS CloudFront CDN (edge: CDG55-P2)
Got: x-amz-cf-id: V9nMGPgDDNGQoqgl4lVDDL2i_babvEIF5yoolciTljDEqxwZo83CRg==
Info::
CDN cache status: FunctionGeneratedResponse from cloudfront
CDN Detected: AWS CloudFront
Provider AWS CloudFront Cache Status FunctionGeneratedResponse from cloudfront Evidence x-amz-cf-id: V9nMGPgDDNGQoqgl4lVDDL2i_babvEIF5yoolciTljDEqxwZo83CRg==
A+
DNS Records
4 A records, 89 ms lookup
PASS
4 A records, 89 ms lookup
Info::
Resolves to 4 IPv4 address(es)
Got: 18.245.199.63, 18.245.199.2, 18.245.199.82, 18.245.199.36
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-125.awsdns-15.com, ns-1664.awsdns-16.co.uk, ns-798.awsdns-35.net, ns-1489.awsdns-58.org
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: 89 ms
Got: 89 ms
A18.245.199.63, 18.245.199.2, 18.245.199.82, 18.245.199.36
AAAA
CNAME
NSns-125.awsdns-15.com, ns-1664.awsdns-16.co.uk, ns-798.awsdns-35.net, ns-1489.awsdns-58.org
MX
1 aspmx.l.google.com
5 alt2.aspmx.l.google.com
5 alt1.aspmx.l.google.com
10 aspmx2.googlemail.com
10 aspmx3.googlemail.com
TXT
_globalsign-domain-verification=e70UZqvudGByIeilV8oO0gubBZi0P7QLakTxKub-zS
botify-site-verification=sGRcFNKzIkHzx1jtsQ7YkiT8hgWB6RiU
SPF v=spf1 include:_spf.google.com include:sendgrid.net include:aspmx.sailthru.com i...
canva-site-verification=JW5MeXNqA7ezvjIRgLOPaQ
apple-domain-verification=FBF7Yx9o3htFHZ7m
onetrust-domain-verification=4bc2331ed4d24c81b7be278e6e1fb58b
hibp-verify=dweb_9nibj6s7woei7t5h43qd3yni
yahoo-verification-key=h5B5VELNOFcyiRDJQWEiNChg+SeClI9Bk9k9daiRPR4=
google-site-verification=JML6gcy7DbE1dA3JB9W4O6EB9uQ8bpOlJTyniVCgd-o
spf2.0/pra include:_spf.google.com include:sendgrid.net include:aspmx.sailthru.c...
anthropic-domain-verification-4va7p1=Uuz4j8MkpGFjBjYBqvNGNuK46
cursor-domain-verification-dc9ngn=XEN4zLZD2K4p5yMB2JFUNxGIk
google-site-verification=Jiabx8hC-zV0E8-hAj40dHCY_oWNIvfqkNe7VFnGbCs
openai-domain-verification=dv-E4EGw5ZIgYd9B3mwA3dPV5zY
facebook-domain-verification=8kvuco8ljlv8t1aedswjypctrp1pk3
google-site-verification=SprWzGYoIdXdFrUCSyBhXJtHzFjE8FAQNlTamgKenhU
google-site-verification=y1w1HGdtmQcg92Uy4JtubYkFtDDshCwmDXTFCgjpr-Y
google-site-verification=7kTMmLFa8kfzTFffAv659zZAhSvDX5lqnB_yuST-xLY
google-site-verification=sHrvDlgokhtbjBWsn8Dhu616EFRRv8GD0C1AU4_1gl4
cl_verification=a568671a-6112-4bc5-997d-1f06d8389b2e
_globalsign-domain-verification=Prrz12gznJzJiHaajX3CnPfpqK6hhLae0miMSZ_BGa
globalsign-domain-verification=qV_5Us2mt6FO1Ig5hnG4kYHESYAxuH5-qZ0cRXC-Ig
MS=ms10049948
_globalsign-domain-verification=Ca9ol7KyPTrPtyGjL1BqGx_wv6SymozDmCXhHJveUr
CAALookup not available with standard resolver
Resolved in 89 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), 251 ms total
PASS
1 redirect(s), 251 ms total
Info::
Single redirect
Got: https://khanacademy.org → https://www.khanacademy.org/ (308)
Info::
WWW normalization redirect

https://khanacademy.org

52 ms · HTTP/1.1

308

https://www.khanacademy.org/

198 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://khanacademy.org30852 msHTTP/1.1CloudFront
2https://www.khanacademy.org/200198 msHTTP/1.1

See the visual redirect chain in the HTTP Probe tab →

A+
Domain Intelligence
khanacademy.org — via GoDaddy.com, LLC, 20 years, 4 months old, hosted on AWS
PASS
khanacademy.org — via GoDaddy.com, LLC, 20 years, 4 months old, hosted on AWS
Info::
Domain registered until Mar 14, 2029 (2 years, 11 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

976 days

March 14, 2029

SSL certificate

239 days

Issued by Amazon

Domain age

20 years, 4 months

Registered March 14, 2006

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

18.245.199.2

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 March 14, 2006 (20 years, 4 months ago)
Expires March 14, 2029 (2 years, 11 months)
Last Updated July 4, 2024
Name Servers ns-1489.awsdns-58.org, ns-125.awsdns-15.com, ns-1664.awsdns-16.co.uk, ns-798.awsdns-35.net
DNSSEC Not enabled
Hosting
IP Address 18.245.199.2
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.4s)

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 89 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
37 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.
89 ms
Total Time Total request time from DNS lookup through full response.
89 ms

Connection waterfall

DNS Lookup 37 ms TCP Connect 16 ms TLS Handshake 18 ms Server Processing 18 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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