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https://www.haskell.org

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.

B
DNS Records
1 A records, 47 ms lookup
REVIEW
1 A records, 47 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 142.93.179.24
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
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: www-combo-nix.haskell.org
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: 47 ms
Got: 47 ms
A142.93.179.24
AAAA—
CNAMEwww-combo-nix.haskell.org
NS—
MX—
TXT—
CAALookup not available with standard resolver
Resolved in 47 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

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

B
Crawlability
robots.txt present, no sitemap
REVIEW
robots.txt present, no sitemap
Info::
robots.txt is present
Got: 104 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 104 B Sitemaps referenced 0 User-agents AhrefsBot, * Blocking No — crawling allowed
User-agent: AhrefsBot
Disallow: /

User-agent: *
Disallow: /hoogle/?hoogle

User-agent: *
Crawl-delay: 5
sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

B
TLS Certificate Expiry & Recommendations
62 days until leaf cert expires — 2 issues to address
REVIEW

Certificate validity

62
days left
0d 30d 60d 90d+

Recommended actions

  • Enable HSTS: Strict-Transport-Security: max-age=31536000; includeSubDomains
  • 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.haskell.org

https://www.haskell.org

368 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://www.haskell.org200368 msHTTP/1.1nginx
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: www)
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

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

Preferred variant: www

HTTP → HTTPS

301http://www.haskell.org/ → https://www.haskell.org/

Consistent

A+
Domain Intelligence
haskell.org — via NameCheap, Inc., 29 years, 8 months old, hosted on DigitalOcean
PASS
haskell.org — via NameCheap, Inc., 29 years, 8 months old, hosted on DigitalOcean
Info::
Domain registered until Dec 11, 2027 (1 years, 8 months remaining)
Info::
DNSSEC is enabled
Info::
Registrar: NameCheap, Inc.
Info::
Hosting: DigitalOcean
Got: AS14061
Domain expiry

517 days

December 11, 2027

SSL certificate

62 days

Issued by Let's Encrypt

Domain age

29 years, 8 months

Registered December 12, 1996

DNSSEC

Enabled

Protects against DNS spoofing

Hosting

DigitalOcean

ASN AS14061

142.93.179.24

Registrar

NameCheap, Inc.

Lock status unknown 2 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar NameCheap, Inc.
Created December 12, 1996 (29 years, 8 months ago)
Expires December 11, 2027 (1 years, 8 months)
Last Updated December 19, 2019
Name Servers lex.ns.cloudflare.com, pola.ns.cloudflare.com
DNSSEC Enabled
Hosting
IP Address 142.93.179.24
ASN AS14061 (DIGITALOCEAN-ASN - DigitalOcean, LLC, US)
Provider DigitalOcean
Data source: rdap (0.4s)
A+
HTTP Probe Timing
Total 361 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
74 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
94 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
97 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
361 ms
Total Time Total request time from DNS lookup through full response.
361 ms

Connection waterfall

DNS Lookup 74 ms TCP Connect 94 ms TLS Handshake 97 ms Server Processing 96 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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