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https://douban.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
78
GRADE
C
FIX
2
REVIEW
4
PASS
3
INFO
0
Probed from Madrid, Spain
301 Moved Permanently
Checks
9
3 PASS 4 REVIEW 2 FIX
D
URL Variants
Action
www/non-www, trailing slash, HTTP→HTTPS
FIX
www/non-www, trailing slash, HTTP→HTTPS
Critical::
Both www and non-www versions serve content
Got: Both variants return 200 Expected: One variant 301-redirects to the other
Critical::
HTTP version does not redirect to HTTPS
Got: HTTP 301 Expected: 301 redirect to HTTPS

www / non-www

200https://www.douban.com/
200https://douban.com/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://douban.com/ → http://www.douban.com/

HTTP version does not redirect to HTTPS

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
Redirect Chain
1 redirect(s), 1878 ms total
REVIEW
1 redirect(s), 1878 ms total
Info::
Single redirect
Got: https://douban.com → https://www.douban.com/ (301)
Info::
WWW normalization redirect
Warning::
Redirect overhead: 1878 ms total
Got: 1878 ms

https://douban.com

887 ms · HTTP/1.1

301

https://www.douban.com/

991 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://douban.com301887 msHTTP/1.1dae
2https://www.douban.com/200991 msHTTP/1.1dae

See the visual redirect chain in the HTTP Probe tab →

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
HTTP Probe Timing
Total 956 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
36 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
229 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
461 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
956 ms
Total Time Total request time from DNS lookup through full response.
956 ms

Connection waterfall

DNS Lookup 36 ms TCP Connect 229 ms TLS Handshake 461 ms Server Processing 230 ms Content Transfer 0 ms
B
TLS Certificate Expiry & Recommendations
53 days until leaf cert expires — 6 issues to address
REVIEW

Certificate validity

53
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
  • 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
A
DNS Records
3 A records, 288 ms lookup
PASS
3 A records, 288 ms lookup
Info::
Resolves to 3 IPv4 address(es)
Got: 120.53.130.158, 81.70.124.99, 140.143.177.206
Info::
No IPv6 (AAAA) records
Info::
2 nameserver(s) configured
Got: ns4.dnsv4.com, ns3.dnsv4.com
Info::
3 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
Warning::
DNS resolution is slow (288 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 288 ms
A120.53.130.158, 81.70.124.99, 140.143.177.206
AAAA—
CNAME—
NSns4.dnsv4.com, ns3.dnsv4.com
MX
10 mx1.feishu.cn
20 mx2.feishu.cn
30 mx3.feishu.cn
TXT
SPF v=spf1 include:feishu-spf.mail.douban.com ~all
_7taq71qhdd4d8aex977o81h07frjhgl
CAALookup not available with standard resolver
Resolved in 288 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.

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

A+
Crawlability
robots.txt present, sitemap with 10581 URLs
PASS
robots.txt present, sitemap with 10581 URLs
Info::
robots.txt is present
Got: 895 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 10581 entries
Info::
Sitemap index with 10581 child sitemaps
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 895 B Sitemaps referenced 2 User-agents Wandoujia Spider, Mediapartners-Google, * Blocking No — crawling allowed
User-agent: *
Disallow: /subject_search
Disallow: /amazon_search
Disallow: /search
Disallow: /group/search
Disallow: /event/search
Disallow: /celebrities/search
Disallow: /location/drama/search
Disallow: /forum/
Disallow: /new_subject
Disallow: /service/iframe
Disallow: /j/
Disallow: /link2/
Disallow: /recommend/
Disallow: /doubanapp/card
Disallow: /update/topic/
Disallow: /share/
Disallow: /people/*/collect
Disallow: /people/*/wish
Disallow: /people/*/all
Disallow: /people/*/do
Allow: /ads.txt
Sitemap: https://www.douban.com/sitemap_index.xml
Sitemap: https://www.douban.com/sitemap_updated_index.xml
# Crawl-delay: 5

User-agent: Wandoujia Spider
Disallow: /

User-agent: Mediapartners-Google
Disallow: /subject_search
Disallow: /amazon_search
Disallow: /search
Disallow: /group/search
Disallow: /event/search
Disallow: /celebrities/search
Disallow: /location/drama/search
Disallow: /j/
sitemap.xml 200 OK
Type Sitemap Index URLs 10581 entries Valid XML Yes
Child Sitemaps:
A+
Domain Intelligence
douban.com — via Alibaba Cloud Computing (Beijing) Co., Ltd., 21 years, 10 months old, hosted on Tencent Cloud
PASS
douban.com — via Alibaba Cloud Computing (Beijing) Co., Ltd., 21 years, 10 months old, hosted on Tencent Cloud
Info::
Domain registered until Sep 19, 2027 (1 years, 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: Alibaba Cloud Computing (Beijing) Co., Ltd.
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: Tencent Cloud
Got: AS45090
Domain expiry

431 days

September 19, 2027

SSL certificate

53 days

Issued by Let's Encrypt

Domain age

21 years, 10 months

Registered September 19, 2004

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Tencent Cloud

ASN AS45090

81.70.124.99

Registrar

Alibaba Cloud Computing (Beijing) Co., Ltd.

Unlocked 2 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 Alibaba Cloud Computing (Beijing) Co., Ltd.
Created September 19, 2004 (21 years, 10 months ago)
Expires September 19, 2027 (1 years, 5 months)
Last Updated December 29, 2025
Name Servers ns3.dnsv4.com, ns4.dnsv4.com
DNSSEC Not enabled
Hosting
IP Address 81.70.124.99
ASN AS45090 (TENCENT-NET-AP Shenzhen Tencent Computer Systems Company Limited, CN)
Provider Tencent Cloud
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

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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