Domain Checker

Domain Checker: Core Features & Principles

When a website is inaccessible or DNS settings have just been changed, you need to immediately verify if the resolution has taken effect and whether the server's HTTP status is normal. The Domain Checker allows you to input a domain name to query its DNS records (A/AAAA/CNAME, etc.) in real-time. It simultaneously checks the HTTP/HTTPS response status code and response time, helping webmasters and developers troubleshoot network connectivity issues all in one place. The tool works by sending resolution requests to public DNS servers and simulating HTTP GET requests to return the actual resolved IP addresses and status codes.

Why Choose Our Domain Checker?

• Outputs both DNS records and HTTP status codes simultaneously, allowing you to complete basic connectivity checks without switching between multiple tools.
• Supports common record types (A, AAAA, CNAME), covering both IPv4 and IPv6 address queries.
• Results directly display the resolved IP, response status code, and response time. The data is clear, and no software installation is required.

How to Use

1. Enter the domain name you want to check (e.g., example.com) in the input box. Do not add the http:// prefix.
2. Click the "Check" button. The tool will automatically perform a DNS lookup and HTTP status check.
3. View the results: The DNS record list will show the record type, resolved value, and TTL. The HTTP status section will display the status code (e.g., 200, 301, 404), response time, and any redirect URLs. Example: Entering "baidu.com" returns an A record IP like 110.242.68.66, an HTTP status code of 200, and a response time of about 0.23 seconds.

Frequently Asked Questions (FAQ)

• Q: Why do the DNS lookup results show multiple IP addresses?
  A: The domain may have multiple A records configured for load balancing or disaster recovery. The checker will list all currently resolved IP addresses, which all point to the same domain.
• Q: What does it mean when the HTTP status check returns "Request Timeout"?
  A: It means a connection could not be established or a response was not received from the server within the timeout period. This usually indicates that the target server is unreachable, blocked by a firewall, or the resolved IP is incorrect. We recommend verifying the DNS resolution results.

Important Notes

Please enter a valid domain name (without the protocol header), such as "example.com". The test results are influenced by the local network environment and DNS cache, so queries from different regions may vary. The HTTP check defaults to using the GET method to request http://domain/. If the site forces HTTPS, it will return a 301 redirect status code, which is completely normal. This tool is strictly for network diagnostic purposes and does not log any user query data, so you can use it with confidence.

Technical Notes & Tips

When troubleshooting DNS propagation issues, you can first use this tool to get the resolved IP and compare it with your DNS provider's configuration. If the HTTP status code is a 301 permanent redirect, you should check the website's canonical domain settings. A 5xx status code usually indicates an error with the origin server. Typical example: Querying "www.example.com" returns an HTTP 301 redirecting to "example.com". It is recommended to standardize your primary business domain to the non-www version and ensure proper CNAME or A record pointing in your DNS settings.