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Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
90
GRADE
A
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
6 PASS 3 REVIEW
B
Redirect Chain
2 redirect(s), 320 ms total
REVIEW
2 redirect(s), 320 ms total
Warning::
2 redirects before reaching final URL
Each redirect adds latency. Try to minimize the chain to 1 hop.
Info::
HTTP to HTTPS redirect present
Info::
WWW normalization redirect
Warning::
2-hop chain could be reduced to 1 hop
Redirect directly from https://doxygen.org to https://www.doxygen.nl/
Info::
Cross-domain redirect detected

https://doxygen.org

97 ms · HTTP/1.1

301

http://www.doxygen.nl/

87 ms · HTTP/1.1

301

https://www.doxygen.nl/

137 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://doxygen.org30197 msHTTP/1.1cloudflare
2http://www.doxygen.nl/30187 msHTTP/1.1cloudflare
3https://www.doxygen.nl/200137 msHTTP/1.1cloudflare

See the visual redirect chain in the HTTP Probe tab →

Each redirect adds latency. Try to minimize the chain to 1 hop.

Why this matters

Redirect chain — each hop adds latency; combine into one redirect where possible.

Source: Google Search Central / web.dev

Redirect directly from https://doxygen.org to https://www.doxygen.nl/

Why this matters

Redirect chain could be flattened to one hop — server config tweak removes intermediate latency.

Source: web.dev

B
Crawlability
robots.txt present, no sitemap
REVIEW
robots.txt present, no sitemap
Info::
robots.txt is present
Got: 1248 bytes
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.
Info::
robots.txt does not reference a sitemap
Add a 'Sitemap:' directive to robots.txt so search engines can discover your sitemap.

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

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 1248 B Sitemaps referenced 0 User-agents Blocking No — crawling allowed
# As a condition of accessing this website, you agree to abide by the following
# content signals:

# (a)  If a content-signal = yes, you may collect content for the corresponding
#      use.
# (b)  If a content-signal = no, you may not collect content for the
#      corresponding use.
# (c)  If the website operator does not include a content signal for a
#      corresponding use, the website operator neither grants nor restricts
#      permission via content signal with respect to the corresponding use.

# The content signals and their meanings are:

# search:   building a search index and providing search results (e.g., returning
#           hyperlinks and short excerpts from your website's contents). Search does not
#           include providing AI-generated search summaries.
# ai-input: inputting content into one or more AI models (e.g., retrieval
#           augmented generation, grounding, or other real-time taking of content for
#           generative AI search answers).
# ai-train: training or fine-tuning AI models.

# ANY RESTRICTIONS EXPRESSED VIA CONTENT SIGNALS ARE EXPRESS RESERVATIONS OF
# RIGHTS UNDER ARTICLE 4 OF THE EUROPEAN UNION DIRECTIVE 2019/790 ON COPYRIGHT
# AND RELATED RIGHTS IN THE DIGITAL SINGLE MARKET.

sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

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

Certificate validity

61
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
2 A records, 44 ms lookup
PASS
2 A records, 44 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 104.21.65.7, 172.67.138.177
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2606:4700:3033::ac43:8ab1, 2606:4700:3037::6815:4107
Info::
2 nameserver(s) configured
Got: maleah.ns.cloudflare.com, kolton.ns.cloudflare.com
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: 44 ms
Got: 44 ms
A104.21.65.7, 172.67.138.177
AAAA2606:4700:3033::ac43:8ab1, 2606:4700:3037::6815:4107
CNAME
NSmaleah.ns.cloudflare.com, kolton.ns.cloudflare.com
MX
TXT
CAALookup not available with standard resolver
Resolved in 44 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.

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)

A+
IPv6 Readiness
IPv6 reachable (16 ms)
PASS
IPv6 reachable (16 ms)
Info::
IPv6 is configured and reachable at 2606:4700:3033::ac43:8ab1, 2606:4700:3037::6815:4107
Got: 16 ms connect
IPv6 Ready
AAAA Records 2606:4700:3033::ac43:8ab1, 2606:4700:3037::6815:4107 Connection Reachable (16 ms)
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
www/non-www redirect configured correctly (preferred: non-www)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

301https://www.doxygen.org/
200https://doxygen.org/

Preferred variant: non-www

HTTP → HTTPS

301http://doxygen.org/ https://doxygen.org/

Consistent

A+
Domain Intelligence
doxygen.org — via Hosting Concepts B.V. d/b/a Registrar.eu, 26 years, 4 months old
PASS
doxygen.org — via Hosting Concepts B.V. d/b/a Registrar.eu, 26 years, 4 months old
Info::
Domain registered until Apr 11, 2027 (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: Hosting Concepts B.V. d/b/a Registrar.eu
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

273 days

April 11, 2027

SSL certificate

61 days

Issued by Google Trust Services

Domain age

26 years, 4 months

Registered April 11, 2000

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2606:4700:3037::6815:4107

Registrar

Hosting Concepts B.V. d/b/a Registrar.eu

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 Hosting Concepts B.V. d/b/a Registrar.eu
Created April 11, 2000 (26 years, 4 months ago)
Expires April 11, 2027 (11 months)
Last Updated April 11, 2026
Name Servers kolton.ns.cloudflare.com, maleah.ns.cloudflare.com
DNSSEC Not enabled
Hosting
IP Address 2606:4700:3037::6815:4107
Data source: rdap (0.7s)

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

Connection waterfall

DNS Lookup 51 ms TCP Connect 17 ms TLS Handshake 22 ms Server Processing 69 ms Content Transfer 0 ms
A
CDN & Delivery
Cloudflare (DYNAMIC)
PASS
Cloudflare (DYNAMIC)
Info::
Site is served via Cloudflare CDN (edge: CDG)
Got: cf-ray: 9efefcbc98fe46a0-CDG
Info::
CDN cache status: DYNAMIC
CDN Detected: Cloudflare
Provider Cloudflare Cache Status DYNAMIC Evidence cf-ray: 9efefcbc98fe46a0-CDG
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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