check web redirect url status code checker

Check server response of

Server response
NS records
Whois domain
Response headers
Request headers
Raw HTML code
521 Web Server Is Down - gpcns.com
HTTP Status: 521
User-Agent: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; [email protected])
Date: Tue, 20 May 2025 20:35:31 GMT
Content-Type: text/plain; charset=UTF-8
Content-Length: 15
Connection: keep-alive
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v4?s=HT5RbNcmWDfdLSrqmq1TwrtNEZf%2FFTUcSw3o2BDW1bW1p7ueB3EEb8QHc4Si1FGNxwkRiKiOOuJKRCg%2FGUsLPNyDSKGD2uviDoML4bmVhwSXLpW03RcQcrWZw56VxD%2FMbzXiQi8eT28%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
X-Frame-Options: SAMEORIGIN
Referrer-Policy: same-origin
Cache-Control: private, max-age=0, no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Expires: Thu, 01 Jan 1970 00:00:01 GMT
Server: cloudflare
CF-RAY: 942e9efabed3e4bc-AMS
alt-svc: h3=":443"; ma=86400
server-timing: cfL4;desc="?proto=TCP&rtt=30245&min_rtt=30245&rtt_var=15122&sent=1&recv=3&lost=0&retrans=0&sent_bytes=0&recv_bytes=165&delivery_rate=0&cwnd=249&unsent_bytes=0&cid=0000000000000000&ts=0&x=0"
GET / HTTP/1.1
Host: gpcns.com
Accept: */*
User-Agent: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; [email protected])

error code: 521

Whois info of domain

Domain Name: GPCNS.COM
Registry Domain ID: 2824701192_DOMAIN_COM-VRSN
Registrar WHOIS Server: whoisserver.iNET.vn
Registrar URL: http://www.iNET.vn
Updated Date: 2024-10-23T01:42:09Z
Creation Date: 2023-10-26T09:11:50Z
Registry Expiry Date: 2025-10-26T09:11:50Z
Registrar: iNET SOFTWARE COMPANY LIMITED
Registrar IANA ID: 3234
Registrar Abuse Contact Email: [email protected]
Registrar Abuse Contact Phone: +84.904888023
Domain Status: clientTransferProhibited https://icann.org/epp#clientTransferProhibited
Name Server: LILY.NS.CLOUDFLARE.COM
Name Server: SKIP.NS.CLOUDFLARE.COM
DNSSEC: unsigned
URL of the ICANN Whois Inaccuracy Complaint Form: https://www.icann.org/wicf/
>>> Last update of whois database: 2025-05-20T20:35:21Z <<<
For more information on Whois status codes, please visit https://icann.org/epp
NOTICE: The expiration date displayed in this record is the date the
TERMS OF USE: You are not authorized to access or query our Whois
by the following terms of use: You agree that you may use this Data only
to: (1) allow, enable, or otherwise support the transmission of mass