Website diagnostics
DNS Checker & Lookup
Use a free DNS checker and lookup tool with Web Health. Inspect A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, and SRV records for any domain, including reverse DNS results.
Understanding DNS Record Types & Hierarchy
The Domain Name System (DNS) functions as the address book of the Internet. Running a comprehensive DNS lookup helps domain owners and sysadmins audit web hosting pointers, email routing, SSL authorization, and domain verification records.
Common DNS Record Types
- A Record: Maps domain hostname to an IPv4 address.
- AAAA Record: Maps domain hostname to an IPv6 address.
- CNAME Record: Creates an alias pointing to another domain name.
- MX Record: Directs inbound email to designated mail servers.
- TXT Record: Stores text data for SPF, DKIM, DMARC, and domain verification.
- NS Record: Identifies authoritative name servers for the domain zone.
DNS Management Best Practices
- Lower TTL Before Migrations: Reduce TTL to 300s prior to moving IP hosting servers.
- Configure CAA Records: Restrict authorized SSL certificate issuers.
- Redundant Name Servers: Ensure at least two geographically separated NS hosts.
- Avoid CNAME at Root: Never place CNAME records on the apex domain (@ root).
Frequently Asked Questions
A DNS (Domain Name System) lookup queries authoritative name servers to resolve human-readable domain names (e.g. example.com) into IP addresses (A/AAAA records) and other server resource routing records.