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https://backlinko.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
92
GRADE
A
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from Madrid, Spain
200 OK
Checks
9
6 PASS 3 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

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

Certificate validity

36
days left
0d 30d 60d 90d+

Recommended actions

  • Add includeSubDomains to the HSTS directive
  • Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
  • 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
Netlify
REVIEW
Netlify
Info::
Site is served via Netlify CDN
Got: x-nf-request-id: 01KPRXHF16GSEZSHMCYSFSY8DT
CDN Detected: Netlify
Provider Netlify Evidence x-nf-request-id: 01KPRXHF16GSEZSHMCYSFSY8DT
A+
DNS Records
2 A records, 36 ms lookup
PASS
2 A records, 36 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 3.33.186.135, 15.197.167.90
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: dns1.p02.nsone.net, dns3.p02.nsone.net, dns4.p02.nsone.net, dns2.p02.nsone.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::
No SPF record found in TXT records
SPF helps prevent email spoofing. Add a TXT record starting with 'v=spf1'.
Info::
DNS resolution time: 36 ms
Got: 36 ms
A3.33.186.135, 15.197.167.90
AAAA—
CNAME—
NSdns1.p02.nsone.net, dns3.p02.nsone.net, dns4.p02.nsone.net, dns2.p02.nsone.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
google-site-verification=ydTK7Nghc98RUm0afOS4OqnCV8S0AP3sLuFCNXbrkxw
google-site-verification=rGQeOIsP0BszYIo9IeHwMjx6V2DTXDVb8svLW1vP-rE
google-site-verification=dxxKd2phKddRux7_2OUuEe6NzYxZe7MoRE-Ht4l7AMg
google-site-verification=Eq_cnun_H4DceU4N_NfJUG9UMrSaCoFiVw1IpG3HcfI
google-site-verification=G1Z9KnHYpbhaEkwi19NGXHDbWHXPdCCWLc-K1Eviqoo
CAALookup not available with standard resolver
Resolved in 36 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+
Redirect Chain
No redirects — direct access
PASS
No redirects — direct access
Info::
No redirects — direct access
Got: https://backlinko.com

https://backlinko.com

197 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://backlinko.com200197 msHTTP/1.1Netlify
A+
Crawlability
robots.txt present, sitemap with 10 URLs
PASS
robots.txt present, sitemap with 10 URLs
Info::
robots.txt is present
Got: 418 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 10 entries
Info::
Sitemap index with 10 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 418 B Sitemaps referenced 1 User-agents *, Googlebot Blocking No — crawling allowed
User-agent: *
Disallow: /tag/
Disallow: /wp-admin/
Disallow: /blog/search
Sitemap: https://backlinko.com/sitemap_index.xml

# SEO experiment: Only Googlebot is allowed to crawl /nexorbaloptimization — all other bots are blocked

# Allow Googlebot to access the specific page
User-agent: Googlebot
Allow: /nexorbaloptimization

# Block all other bots from that page only
User-agent: *
Disallow: /nexorbaloptimization
sitemap.xml 200 OK
Type Sitemap Index URLs 10 entries Valid XML Yes
Child Sitemaps:
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.backlinko.com/
200https://backlinko.com/

Preferred variant: non-www

HTTP → HTTPS

301http://backlinko.com/ → https://backlinko.com/

Consistent

A+
Domain Intelligence
backlinko.com — via MarkMonitor Inc., 14 years, 9 months old, hosted on AWS
PASS
backlinko.com — via MarkMonitor Inc., 14 years, 9 months old, hosted on AWS
Info::
Domain registered until Sep 28, 2035 (9 years, 6 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: MarkMonitor Inc.
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

3391 days

September 28, 2035

SSL certificate

36 days

Issued by Let's Encrypt

Domain age

14 years, 9 months

Registered September 28, 2011

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS16509

3.33.186.135

Registrar

MarkMonitor Inc.

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 MarkMonitor Inc.
Created September 28, 2011 (14 years, 9 months ago)
Expires September 28, 2035 (9 years, 6 months)
Last Updated February 19, 2026
Name Servers dns1.p02.nsone.net, dns2.p02.nsone.net, dns3.p02.nsone.net, dns4.p02.nsone.net
DNSSEC Not enabled
Hosting
IP Address 3.33.186.135
ASN AS16509 (AMAZON-02 - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.3s)

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

Connection waterfall

DNS Lookup 28 ms TCP Connect 33 ms TLS Handshake 34 ms Server Processing 139 ms Content Transfer 63 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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