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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
88
GRADE
B
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from New York, United Stated
200 OK
Checks
9
6 PASS 3 REVIEW
B
DNS Records
2 A records, 26 ms lookup
REVIEW
2 A records, 26 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 216.150.16.129, 216.150.1.129
Info::
No IPv6 (AAAA) records
Warning::
CNAME record at zone apex
A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.
Got: 4b9af6920c9c4c4c.vercel-dns-016.com
Info::
No NS records found
Info::
No MX records — email not configured via DNS
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 26 ms
Got: 26 ms
A216.150.16.129, 216.150.1.129
AAAA
CNAME4b9af6920c9c4c4c.vercel-dns-016.com
NS
MX
TXT
CAALookup not available with standard resolver
Resolved in 26 ms

A CNAME at the zone apex can break MX and NS records. Use ALIAS/ANAME or A records instead.

Why this matters

CNAME at the apex (example.com) breaks every other apex record (MX, TXT, NS) — DNS-protocol violation per RFC 1034.

Learn more

RFC 1034 forbids CNAME alongside other records at the same name. Some DNS providers offer ALIAS / ANAME / flattened-CNAME records that work around this — use those instead. Otherwise apex-level CNAME breaks email (no MX), domain ownership verification (no TXT), and more.

Source: RFC 1034

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.

SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.

Why this matters

Without SPF, receiving servers can't validate sending IPs — your domain is easier to spoof in phishing.

Learn more

SPF complements DMARC. Both should be published. SPF records list authorized sending IPs (e.g., `v=spf1 include:_spf.google.com ~all` for Google Workspace). After publishing, verify in Google Postmaster Tools or mxtoolbox.

Source: RFC 7208 (SPF)

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

Certificate validity

27
days left
0d 30d 60d 90d+
Renew soon — under 30 days remaining

Recommended actions

  • Renew certificate — 27 days remaining
  • 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+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://www.prefect.io

https://www.prefect.io

82 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.prefect.io20082 msHTTP/1.1Vercel
A+
Crawlability
robots.txt present, sitemap with 2 URLs
PASS
robots.txt present, sitemap with 2 URLs
Info::
robots.txt is present
Got: 125 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 2 entries
Info::
Sitemap index with 2 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 125 B Sitemaps referenced 1 User-agents * Blocking No — crawling allowed
User-Agent: *
Allow: /
Disallow: /api/
Disallow: /login
Disallow: /signup

Sitemap: https://www.prefect.io/sitemap-index.xml

sitemap.xml 200 OK
Type Sitemap Index URLs 2 entries Valid XML Yes
A
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Warning::
HTTP→HTTPS redirect uses 302 instead of 301
Got: 302 temporary redirect Expected: 301 permanent redirect

www / non-www

200https://www.prefect.io/
307https://prefect.io/

HTTP → HTTPS

308http://www.prefect.io/ https://www.prefect.io/

Use 301 (permanent) instead of 302 (temporary)

A+
Domain Intelligence
prefect.io — via Key-Systems GmbH, 9 years, 2 months old, hosted on AWS
PASS
prefect.io — via Key-Systems GmbH, 9 years, 2 months old, hosted on AWS
Info::
Domain registered until Mar 25, 2027 (11 months remaining)
Info::
Registrar: Key-Systems GmbH
Info::
Hosting: AWS
Got: AS16509
Domain expiry

283 days

March 25, 2027

SSL certificate

27 days

Issued by Let's Encrypt

Domain age

9 years, 2 months

Registered March 25, 2017

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

216.150.1.1

Registrar

Key-Systems GmbH

Lock status unknown 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Renew the TLS certificate or verify auto-renewal is working
Registrar Key-Systems GmbH
Created March 25, 2017 (9 years, 2 months ago)
Expires March 25, 2027 (11 months)
Last Updated March 15, 2026
Name Servers ns-cloud-b1.googledomains.com, ns-cloud-b2.googledomains.com, ns-cloud-b3.googledomains.com, ns-cloud-b4.googledomains.com
Registrant c/o whoisproxy.com
Hosting
IP Address 216.150.1.1
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: whois (0.6s)
A+
HTTP Probe Timing
Total 101 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
23 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.
30 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
99 ms
Total Time Total request time from DNS lookup through full response.
102 ms

Connection waterfall

DNS Lookup 23 ms TCP Connect 1 ms TLS Handshake 30 ms Server Processing 45 ms Content Transfer 3 ms
A+
CDN & Delivery
Vercel (HIT)
PASS
Vercel (HIT)
Info::
Site is served via Vercel CDN
Got: x-vercel-id: iad1::iad1::grxr2-1775594076994-c3563501ea64
Info::
CDN cache status: HIT
CDN Detected: Vercel
Provider Vercel Cache Status HIT Evidence x-vercel-id: iad1::iad1::grxr2-1775594076994-c3563501ea64
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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