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https://zalo.me

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
92
GRADE
A
FIX
1
REVIEW
3
PASS
4
INFO
1
Probed from Sao Paulo, Brazil
307 Temporary Redirect
Checks
9
4 PASS 3 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.

B
Redirect Chain
1 redirect(s), 3945 ms total
REVIEW
1 redirect(s), 3945 ms total
Info::
Single redirect
Got: https://zalo.me → https://zalo.me/vi/ (307)
Warning::
Redirect overhead: 3945 ms total
Got: 3945 ms

https://zalo.me

1794 ms · HTTP/1.1

307

https://zalo.me/vi/

2152 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://zalo.me3071794 msHTTP/1.1za-ngx-srv
2https://zalo.me/vi/2002152 msHTTP/1.1za-ngx-srv

See the visual redirect chain in the HTTP Probe tab →

C
HTTP Probe Timing
Action
Total 1689 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
REVIEW
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
328 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
338 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
682 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
1.69 s
Total Time Total request time from DNS lookup through full response.
1.69 s

Connection waterfall

DNS Lookup 328 ms TCP Connect 338 ms TLS Handshake 682 ms Server Processing 341 ms Content Transfer 0 ms
B
TLS Certificate Expiry & Recommendations
83 days until leaf cert expires — 5 issues to address
REVIEW

Certificate validity

83
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 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
2 A records, 338 ms lookup
PASS
2 A records, 338 ms lookup
Info::
Resolves to 2 IPv4 address(es)
Got: 49.213.95.189, 49.213.95.151
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2001:df0:13:1::93, 2001:df0:13:1::99
Info::
4 nameserver(s) configured
Got: zans1.zadns.vn, zans1.zadns.me, zans2.zadns.me, zans2.zadns.vn
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::
SPF record present in TXT
Warning::
DNS resolution is slow (338 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 338 ms
A49.213.95.189, 49.213.95.151
AAAA2001:df0:13:1::93, 2001:df0:13:1::99
CNAME—
NSzans1.zadns.vn, zans1.zadns.me, zans2.zadns.me, zans2.zadns.vn
MX
10 zalo-me.mail.protection.outlook.com
TXT
openai-domain-verification=dv-uGGHCB0vmqsOgOJBOVI4WypD
google-site-verification=W6B6OX-CH4YVR2qoG-rApRzMLtlkKQeHOZfkOO4NX_U
google-site-verification=lpuA40S08EYD9BwfGINK96Y4LC0qkU7CBolRXlaYoT8
SPF v=spf1 a mx include:amazonses.com include:spf.protection.outlook.com include:zap...
CAALookup not available with standard resolver
Resolved in 338 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+
IPv6 Readiness
IPv6 reachable (1449 ms)
PASS
IPv6 reachable (1449 ms)
Info::
IPv6 is configured and reachable at 2001:df0:13:1::93, 2001:df0:13:1::99
Got: 1449 ms connect
IPv6 Ready
AAAA Records 2001:df0:13:1::93, 2001:df0:13:1::99 Connection Reachable (1449 ms)
A+
Crawlability
robots.txt present, sitemap with 10 URLs
PASS
robots.txt present, sitemap with 10 URLs
Info::
robots.txt is present
Got: 66 bytes
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 10 entries
Info::
robots.txt references sitemap
robots.txt 200 OK
Size 66 B Sitemaps referenced 1 User-agents Googlebot Blocking No — crawling allowed
Sitemap: https://zalo.me/sitemap/sitemap.xml
User-agent: Googlebot
sitemap.xml 200 OK
Type URL Set URLs 10 entries Valid XML Yes
Sample URLs:
A+
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
PASS
www/non-www, trailing slash, HTTP→HTTPS
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

307https://www.zalo.me/
200https://zalo.me/

HTTP → HTTPS

301http://zalo.me/ → https://zalo.me/

Consistent

Domain Intelligence
Domain intelligence data not available
INFO
Domain intelligence data not available

RDAP and WHOIS lookup both failed

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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