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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
93
GRADE
A
FIX
0
REVIEW
2
PASS
7
INFO
0
Probed from Sao Paulo, Brazil
301 Moved Permanently
Checks
9
7 PASS 2 REVIEW
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
TLS Certificate Expiry & Recommendations
52 days until leaf cert expires — 3 issues to address
REVIEW

Certificate validity

52
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
A+
DNS Records
1 A records, 19 ms lookup
PASS
1 A records, 19 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 23.185.0.1
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2620:12a:8001::1, 2620:12a:8000::1
Info::
4 nameserver(s) configured
Got: ns-1127.awsdns-12.org, ns-1733.awsdns-24.co.uk, ns-415.awsdns-51.com, ns-797.awsdns-35.net
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: 19 ms
Got: 19 ms
A23.185.0.1
AAAA2620:12a:8001::1, 2620:12a:8000::1
CNAME
NSns-1127.awsdns-12.org, ns-1733.awsdns-24.co.uk, ns-415.awsdns-51.com, ns-797.awsdns-35.net
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
2jr4cb9p4ctf5ymtz4xlp0l4gb0vg304
MS=ms35793585
anthropic-domain-verification-89d5jf=wtjF67F1Bl4WiWz6KdSx0rlc3
apple-domain-verification=GokUpgoQLiVO1pMb
apple-domain-verification=NU1EKMj8yRHxSeqsWIQfl9VpEGdpZx2vlPx-C4ivpdw
atlassian-sending-domain-verification=c0020406-7682-4113-8329-295cb6db900e
google-site-verification=iLMRS8mQyaUFUd1wTpE5XZGQYcBPUADJOwcMsoN6Ei0
google-site-verification=nGJ4sbjTlz5bYzlOuef2xiUW1U1066O-Mmhu3QTuys0
include:spf.mandrillapp.com ~all
SPF v=spf1 include:_spf.google.com include:_spf.salesforce.com include:_spf.atlassia...
CAALookup not available with standard resolver
Resolved in 19 ms

Multiple A records provide failover if one server goes down.

Why this matters

Single A record means a single point of failure — if that IP goes down, your site is unreachable until DNS TTL expires.

Learn more

Add multiple A records for round-robin failover, or use a managed DNS provider with health-checked failover (Route 53, Cloudflare, NS1). Short TTL (60-300s) lets clients recover faster on outages.

Source: SRE practice / DNS architecture

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), 309 ms total
PASS
1 redirect(s), 309 ms total
Info::
Single redirect
Got: https://exploratorium.edu → https://www.exploratorium.edu/ (301)
Info::
WWW normalization redirect

https://exploratorium.edu

167 ms · HTTP/1.1

301

https://www.exploratorium.edu/

141 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://exploratorium.edu301167 msHTTP/1.1Pantheon
2https://www.exploratorium.edu/405141 msHTTP/1.1CloudFront

See the visual redirect chain in the HTTP Probe tab →

A+
IPv6 Readiness
IPv6 reachable (1 ms)
PASS
IPv6 reachable (1 ms)
Info::
IPv6 is configured and reachable at 2620:12a:8001::1, 2620:12a:8000::1
Got: 1 ms connect
IPv6 Ready
AAAA Records 2620:12a:8001::1, 2620:12a:8000::1 Connection Reachable (1 ms)
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

405https://www.exploratorium.edu/
200https://exploratorium.edu/

HTTP → HTTPS

301http://exploratorium.edu/ https://www.exploratorium.edu/

Consistent

A+
Domain Intelligence
exploratorium.edu — 34 years, 4 months old
PASS
exploratorium.edu — 34 years, 4 months old
Info::
Domain registered until Jul 31, 2027 (1 years, 3 months remaining)
Domain expiry

379 days

July 31, 2027

SSL certificate

52 days

Issued by Let's Encrypt

Domain age

34 years, 4 months

Registered May 28, 1992

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2620:12a:8001::1

Registrar

Registrar unknown

Lock status unknown 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar
Created May 28, 1992 (34 years, 4 months ago)
Expires July 31, 2027 (1 years, 3 months)
Last Updated April 15, 2026
Name Servers ns-1127.awsdns-12.org, ns-415.awsdns-51.com, ns-1733.awsdns-24.co.uk, ns-797.awsdns-35.net
Registrant The Exploratorium
Hosting
IP Address 2620:12a:8001::1
Data source: whois (0.8s)
A+
HTTP Probe Timing
Total 33 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
19 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
6 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
33 ms
Total Time Total request time from DNS lookup through full response.
33 ms

Connection waterfall

DNS Lookup 19 ms TCP Connect 1 ms TLS Handshake 6 ms Server Processing 7 ms Content Transfer 0 ms
A+
CDN & Delivery
Fastly (HIT)
PASS
Fastly (HIT)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-gru-sbsp2090042-GRU
Info::
CDN cache status: HIT
CDN Detected: Fastly
Provider Fastly Cache Status HIT Evidence x-served-by: cache-gru-sbsp2090042-GRU
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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