Infrastructure
· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.FRedirect ChainAction4 redirect(s), 584 ms totalFIX
https://pnas.org
128 ms · HTTP/1.1
https://www.pnas.org/
137 ms · HTTP/1.1
https://www.pnas.org/action/oidcStart?re...
116 ms · HTTP/1.1
https://www.pnas.org/action/oidcStart?re...
104 ms · HTTP/1.1
https://www.pnas.org/action/cookieAbsent
100 ms · HTTP/1.1 FINAL
| # | URL | Status | Time | Protocol | Server |
|---|---|---|---|---|---|
| 1 | https://pnas.org | 301 | 128 ms | HTTP/1.1 | cloudflare |
| 2 | https://www.pnas.org/ | 302 | 137 ms | HTTP/1.1 | cloudflare |
| 3 | https://www.pnas.org/action/oidcStart?re... | 302 | 116 ms | HTTP/1.1 | cloudflare |
| 4 | https://www.pnas.org/action/oidcStart?re... | 302 | 104 ms | HTTP/1.1 | cloudflare |
| 5 | https://www.pnas.org/action/cookieAbsent | 200 | 100 ms | HTTP/1.1 | cloudflare |
See the visual redirect chain in the HTTP Probe tab →
Each redirect adds latency. Try to minimize the chain to 1 hop.
Redirect chain — each hop adds latency; combine into one redirect where possible.
Source: Google Search Central / web.dev
If permanent, use 301 instead.
302 (Found) is for genuinely temporary redirects — if this redirect is permanent, switch to 301 to preserve SEO equity.
Learn more ▾ ▴
Search engines treat 302 as temporary, keeping the original URL indexed and not transferring full link equity to the destination. Use 301 (Moved Permanently) for permanent redirects (HTTP→HTTPS, www-vs-non-www, URL restructures).
Source: Google Search Central
CIPv6 ReadinessActionNo IPv6 supportREVIEW
IPv6 support is increasingly important for global accessibility. About 40% of internet users have IPv6 connectivity.
No AAAA records — same impact as 'no IPv6 (AAAA) records'; IPv6-preferring clients pay extra latency falling back to IPv4.
Source: Google IPv6 stats
BCrawlabilityrobots.txt present, sitemap with 0 URLsREVIEW
Search engines may not be able to parse the sitemap. Fix XML validation errors.
An unparseable sitemap is silently ignored by Google — the URLs it advertises are never queued for crawl.
Learn more ▾ ▴
Google's sitemap parser is strict about XML validity. A single unescaped `&` or unclosed tag invalidates the whole file. Run your sitemap through a validator (Search Console's Sitemaps report flags it) and fix the offending entry. Most generators escape correctly; mistakes usually come from manually-written entries.
Source: sitemaps.org / Google Search Central
An empty sitemap provides no value. Add <url> entries for your pages.
An empty sitemap signals 'no content to index' to Google — actively harmful versus having no sitemap at all.
Learn more ▾ ▴
Google compares URLs in the sitemap against URLs it has crawled. An empty sitemap on a site with thousands of pages signals abandonment. Either populate it correctly (most CMSes auto-generate) or delete the file and let Google crawl normally.
Source: Google Search Central / sitemaps.org
Sitemap: https://www.pnas.org/sitemap-index-1.xml
User-agent: *
Disallow: /action
Disallow: /search
Disallow: /media
Disallow: /servlet/linkout
Disallow: /author/
Disallow: /authored-by/
Disallow: /personalize/
Disallow: /doi/metrics
Disallow: /doi/citedby
Disallow: /doi/reader
Disallow: /doi/ref
Disallow: /doi/epdf/
Disallow: /history/
Allow: /action/showJournal
Allow: /action/showXml
Allow: /action/showFeed
Allow: /action/showfeed
User-agent: facebookexternalhit
User-agent: LinkedInBot
User-agent: Twitterbot
Allow: /
User-agent: GPTBot
Disallow: /
BTLS Certificate Expiry & Recommendations61 days until leaf cert expires — 5 issues to addressREVIEW
Certificate validity
Recommended actions
- Extend HSTS max-age to at least 31536000 (1 year) to meet the preload list criteria
- 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
BCDN & DeliveryCloudflareREVIEW
A+DNS Records2 A records, 15 ms lookupPASS
| A | 104.18.33.155, 172.64.154.101 |
| AAAA | — |
| CNAME | — |
| NS | ishaan.ns.cloudflare.com, saanvi.ns.cloudflare.com |
| MX | — |
| TXT | google-site-verification=xzMG9SIQIFMkhMg-z1FoxTcDa1owuddQERNtSrl-NQc SPF v=spf1 ip4:65.156.0.0/23 include:sendgrid.net ~all |
| CAA | Lookup not available with standard resolver |
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.
A+URL Variantswww/non-www, trailing slash, HTTP→HTTPSPASS
www / non-www
Preferred variant: non-www
HTTP → HTTPS
Consistent
A+Domain Intelligencepnas.org — via Network Solutions, LLC, 30 years, 6 months old, hosted on CloudflarePASS
619 days
March 24, 2028
61 days
Issued by Google Trust Services
30 years, 6 months
Registered March 23, 1996
Not enabled
Protects against DNS spoofing
Cloudflare
ASN AS13335
172.64.154.101
Network Solutions, LLC
Expiry timeline
Recommended actions
- Enable DNSSEC to protect visitors from DNS spoofing
- Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
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.
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