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https://t.cn

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
76
GRADE
C
FIX
2
REVIEW
5
PASS
2
INFO
0
Probed from Amsterdam, Netherlands
301 Moved Permanently
Checks
9
2 PASS 5 REVIEW 2 FIX
F
Redirect Chain
Action
3 redirect(s), 4613 ms total
FIX
3 redirect(s), 4613 ms total
Warning::
3 redirects before reaching final URL
Each redirect adds latency. Try to minimize the chain to 1 hop.
Info::
HTTP to HTTPS redirect present
Info::
Uses 302 (temporary) redirect
If permanent, use 301 instead.
Got: https://weibo.com/
Warning::
Redirect overhead: 4613 ms total
Got: 4613 ms
Info::
Cross-domain redirect detected

https://t.cn

1747 ms · HTTP/1.1

301

http://weibo.com

632 ms · HTTP/1.1

301

https://weibo.com/

1053 ms · HTTP/1.1

302

https://passport.weibo.com/visitor/visit...

1181 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://t.cn3011747 msHTTP/1.1SHANHAI-SERVER
2http://weibo.com301632 msHTTP/1.1SHANHAI-SERVER
3https://weibo.com/3021053 msHTTP/1.1SHANHAI-SERVER
4https://passport.weibo.com/visitor/visit...2001181 msHTTP/1.1nginx

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

If permanent, use 301 instead.

Why this matters

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

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, 882 ms lookup
REVIEW
1 A records, 882 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 123.56.139.83
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 1 IPv6 (AAAA) record(s)
Got: 2408:4000:200::3b4
Info::
4 nameserver(s) configured
Got: ns1.sina.com.cn, ns3.sina.com.cn, ns4.sina.com.cn, ns2.sina.com.cn
Info::
1 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'.
Warning::
DNS resolution is slow (882 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 882 ms
A123.56.139.83
AAAA2408:4000:200::3b4
CNAME
NSns1.sina.com.cn, ns3.sina.com.cn, ns4.sina.com.cn, ns2.sina.com.cn
MX
10 mx.sina.net
TXT
CAALookup not available with standard resolver
Resolved in 882 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

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)

Slow DNS adds latency to every page load. Consider a faster DNS provider.

Why this matters

DNS resolution is slow — anycast DNS providers (Cloudflare, Route 53) typically resolve <50ms globally.

Source: DNS performance benchmarks

B
Crawlability
no robots.txt, no sitemap
REVIEW
no robots.txt, no sitemap
Info::
No robots.txt found
robots.txt is optional but recommended. It tells search engine crawlers which pages to index.
Info::
No sitemap.xml found
A sitemap helps search engines discover and index your pages more efficiently.

robots.txt is optional but recommended. It tells search engine crawlers which pages to index.

Why this matters

No robots.txt — crawlers fetch /robots.txt and get 404; not breaking but means default crawl behavior with no directives or sitemap reference.

Learn more

A minimal robots.txt with `User-agent: * / Allow: / / Sitemap: https://example.com/sitemap.xml` covers the basics. Without it, crawlers behave fine but lose the sitemap signal and can't be selectively blocked from crawl-traps.

Source: robotstxt.org

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 No robots.txt found

No robots.txt found

This is fine for most sites — a missing robots.txt allows all crawling by default.

sitemap.xml No sitemap found

No sitemap found

Adding a sitemap helps search engines discover your pages.

B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Critical::
HTTP version does not redirect to HTTPS
Got: HTTP 301 Expected: 301 redirect to HTTPS

www / non-www

https://www.t.cn/
200https://t.cn/

HTTP → HTTPS

301http://t.cn/ http://weibo.com

HTTP version does not redirect to HTTPS

C
HTTP Probe Timing
Action
Total 1501 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
740 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
188 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
384 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
1.50 s
Total Time Total request time from DNS lookup through full response.
1.50 s

Connection waterfall

DNS Lookup 740 ms TCP Connect 188 ms TLS Handshake 384 ms Server Processing 190 ms Content Transfer 0 ms
B
TLS Certificate Expiry & Recommendations
252 days until leaf cert expires — 4 issues to address
REVIEW

Certificate validity

252
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+
IPv6 Readiness
IPv6 reachable (275 ms)
PASS
IPv6 reachable (275 ms)
Info::
IPv6 is configured and reachable at 2408:4000:200::3b4
Got: 275 ms connect
IPv6 Ready
AAAA Records 2408:4000:200::3b4 Connection Reachable (275 ms)
A+
Domain Intelligence
t.cn — via 北京新网数码信息技术有限公司, 23 years, 5 months old
PASS
t.cn — via 北京新网数码信息技术有限公司, 23 years, 5 months old
Info::
Domain registered until Aug 23, 2029 (3 years, 4 months remaining)
Info::
Registrar: 北京新网数码信息技术有限公司
Info::
Registrar lock is enabled
Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.
Domain expiry

1134 days

August 23, 2029

SSL certificate

252 days

Issued by DigiCert, Inc.

Domain age

23 years, 5 months

Registered March 10, 2003

DNSSEC

Status unknown

Protects against DNS spoofing

Hosting

Unknown

2408:4000:200::3b4

Registrar

北京新网数码信息技术有限公司

Locked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Registrar 北京新网数码信息技术有限公司
Created March 10, 2003 (23 years, 5 months ago)
Expires August 23, 2029 (3 years, 4 months)
Name Servers ns3.sina.com.cn, ns2.sina.com.cn, ns4.sina.com.cn, ns1.sina.com.cn
Hosting
IP Address 2408:4000:200::3b4
Data source: whois (0.9s)

Domain cannot be transferred without explicit unlock from the registrar. This protects against unauthorized transfers.

Why this matters

Registrar lock (clientTransferProhibited et al.) prevents unauthorized domain transfers — strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

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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