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https://nejm.org

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
87
GRADE
B
FIX
1
REVIEW
2
PASS
6
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
6 PASS 2 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.

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
280 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

280
days left
0d 30d 60d 90d+

Recommended actions

  • Prefer TLS 1.3 — TLS 1.2 is acceptable but TLS 1.3 removes RSA key exchange and improves latency
  • 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
3 A records, 2 ms lookup
PASS
3 A records, 2 ms lookup
Info::
Resolves to 3 IPv4 address(es)
Got: 34.232.252.205, 52.2.82.164, 98.90.52.32
Info::
No IPv6 (AAAA) records
Info::
4 nameserver(s) configured
Got: ns-928.awsdns-52.net, ns-165.awsdns-20.com, ns-1284.awsdns-32.org, ns-1559.awsdns-02.co.uk
Info::
2 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: 2 ms
Got: 2 ms
A34.232.252.205, 52.2.82.164, 98.90.52.32
AAAA—
CNAME—
NSns-928.awsdns-52.net, ns-165.awsdns-20.com, ns-1284.awsdns-32.org, ns-1559.awsdns-02.co.uk
MX
10 us-smtp-inbound-1.mimecast.com
10 us-smtp-inbound-2.mimecast.com
TXT
adobe-idp-site-verification=55cac8ffb5b23b50c94d629752efc925f61ea92c1254d16d8bd6...
SPF v=spf1 ip4:54.240.121.128/27 ip4:52.6.112.187 include:us._netblocks.mimecast.com...
4k87v34q679nnktm7msw176n2mjjt2f2
0ed1fe018af5796b96adc34642aa2a42756ef1a82e
atlassian-domain-verification=NNeumMyMPkAxVMrj7qq1zrhVVGl/5usz/MXkCgRheK8j05h3hD...
xVXYh2htSzJmE6VkToy/aGAmNs8cxK2vV+6I70GL/zlQHSbfrd6n2vPKyYeokIK4okHucqCOzxF9J/FL...
onetrust-domain-verification=aea188f6772b4e0a9e7464f3a5d39d88
MS=ms51433796
6hszhhybwmrbh92rpj7m8rm8rclry7gs
docusign=52095567-2918-44fb-ba89-2af8aa120c2b
tz7y9ps639fshlhk6fmljls36vsgmsh2
openai-domain-verification=dv-8uyHnjMDd4ZJ1w1CapYvN7jZ
CAALookup not available with standard resolver
Resolved in 2 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.

A
Redirect Chain
1 redirect(s), 171 ms total
PASS
1 redirect(s), 171 ms total
Info::
Single redirect
Got: https://nejm.org → https://www.nejm.org:443/ (301)
Info::
WWW normalization redirect

https://nejm.org

96 ms · HTTP/1.1

301

https://www.nejm.org:443/

75 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://nejm.org30196 msHTTP/1.1awselb/2.0
2https://www.nejm.org:443/40375 msHTTP/1.1cloudflare

See the visual redirect chain in the HTTP Probe tab →

A
Crawlability
robots.txt present, no sitemap
PASS
robots.txt present, no sitemap
Info::
robots.txt is present
Got: 1423 bytes
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.
Info::
robots.txt references 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

robots.txt 200 OK
Size 1423 B Sitemaps referenced 1 User-agents AdsBot-Google-Mobile, Google-Extended, PerplexityBot, BLEXBot, *, Sosospider, Googlebot, ChatGPT-User, CCBot, SemanticScholarBot, DataForSeoBot, SemrushBot, GPTBot, AdsBot-Google, AhrefsBot Blocking No — crawling allowed
Sitemap: https://www.nejm.org/sitemap-index-1.txt
User-agent: *
Disallow: /action
Disallow: /help
Disallow: /search
Disallow: /feedback
Disallow: /rss
Disallow: /action/clickThrough
Disallow: /action/showLogin
Disallow: /page/account-confirmation-thanks
Disallow: /media
Disallow: /servlet/linkout
Disallow: /author/
Disallow: /doi/mlt/
Allow: /action/showJournal
Allow: /action/showPublications
Allow: /action/showXml
Allow: /media-center/
Allow: /series
Allow: /isbn
Allow: /doi/book

User-agent: Sosospider
Disallow: /

User-agent: AdsBot-Google
User-agent: AdsBot-Google-Mobile
Allow: /

User-agent: Googlebot
Disallow: /action
Disallow: /help
Disallow: /search
Disallow: /feedback
Disallow: /rss
Disallow: /action/clickThrough
Disallow: /action/showLogin
Disallow: /page/account-confirmation-thanks
Disallow: /media
Disallow: /servlet/linkout
Disallow: /author
Disallow: /doi/mlt/
Allow: /action/showJournal
Allow: /action/showPublications
Allow: /action/showXml
Allow: /media-center/
Allow: /series
Allow: /isbn
Allow: /doi/book
Allow: /action/sso

User-agent: GPTBot
Disallow: /

User-agent: ChatGPT-User
Disallow: /

User-agent: CCBot
Disallow: /

User-agent: Google-Extended
Disallow: /

User-agent: PerplexityBot
Disallow: /

User-agent: SemanticScholarBot
Disallow: /

User-agent: AhrefsBot
Disallow: /

User-agent: BLEXBot
Disallow: /

User-agent: DataForSeoBot
Disallow: /

User-agent: SemrushBot
Disallow: /
sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

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

403https://www.nejm.org/
200https://nejm.org/

HTTP → HTTPS

302http://nejm.org/ → https://nejm.org:443/

Use 301 (permanent) instead of 302 (temporary)

A+
Domain Intelligence
nejm.org — via Amazon Registrar, Inc., 31 years, 11 months old, hosted on AWS
PASS
nejm.org — via Amazon Registrar, Inc., 31 years, 11 months old, hosted on AWS
Info::
Domain registered until Oct 7, 2026 (5 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: Amazon Registrar, 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: AS14618
Domain expiry

84 days

October 7, 2026

SSL certificate

280 days

Issued by Amazon

Domain age

31 years, 11 months

Registered October 8, 1994

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

AWS

ASN AS14618

34.232.252.205

Registrar

Amazon Registrar, Inc.

Unlocked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Renew the domain or enable auto-renewal to prevent accidental expiry
  • Enable DNSSEC to protect visitors from DNS spoofing
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar Amazon Registrar, Inc.
Created October 8, 1994 (31 years, 11 months ago)
Expires October 7, 2026 (5 months)
Last Updated September 7, 2025
Name Servers ns-1284.awsdns-32.org, ns-1559.awsdns-02.co.uk, ns-165.awsdns-20.com, ns-928.awsdns-52.net
DNSSEC Not enabled
Hosting
IP Address 34.232.252.205
ASN AS14618 (AMAZON-AES - Amazon.com, Inc., US)
Provider AWS
Data source: rdap (0.4s)

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

Connection waterfall

DNS Lookup 1 ms TCP Connect 98 ms TLS Handshake 198 ms Server Processing 99 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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