DNS Lookup

The Domain Name System (DNS) is the internet's phonebook. It translates human-readable domain names like google.com into machine-readable IP addresses like 142.250.80.46. Every time you visit a website, your device performs a DNS lookup to find the server's IP address. This process is fundamental to how the internet works, and understanding DNS records is essential for web developers, system administrators, and security professionals.

A and AAAA Records

A records map a domain to an IPv4 address (e.g., 93.184.216.34). AAAA records (also called "quad-A") serve the same purpose but for IPv6 addresses (e.g., 2606:2800:220:1:248:1893:25c8:1946). Most domains have both A and AAAA records to support connections over both IP versions. When a domain has multiple A records, DNS clients typically use round-robin load balancing to distribute traffic.

CNAME Records

A CNAME (Canonical Name) record creates an alias from one domain to another. For example, www.example.com might be a CNAME pointing to example.com, or a CDN hostname like d1234.cloudfront.net. CNAME records are commonly used with CDNs, load balancers, and SaaS platforms. A key rule is that a CNAME cannot coexist with other record types at the same name, and CNAME records cannot be placed at the zone apex (the bare domain).

MX Records

MX (Mail Exchange) records specify the mail servers responsible for receiving email for a domain. Each MX record has a priority value (lower numbers indicate higher priority). When sending an email to user@example.com, the sending mail server queries the MX records for example.com to find where to deliver the message. Multiple MX records with different priorities provide failover if the primary mail server is unavailable.

NS Records

NS (Name Server) records identify the authoritative DNS servers for a domain. These servers hold the official DNS records for the domain and respond to queries from recursive resolvers. When you register a domain, you configure NS records to point to your DNS provider (e.g., Cloudflare, AWS Route 53, Google Cloud DNS). Changes to NS records can take up to 48 hours to propagate globally.

TXT Records

TXT records store arbitrary text data associated with a domain. They are widely used for domain ownership verification (e.g., Google Search Console, Microsoft 365), email authentication (SPF, DKIM, DMARC), and security policies. An SPF record like v=spf1 include:_spf.google.com ~all specifies which servers are authorized to send email on behalf of the domain. DMARC records define policies for handling emails that fail authentication checks.

SOA Records

The SOA (Start of Authority) record contains administrative information about the DNS zone, including the primary nameserver, the responsible party's email address, the zone serial number, and timing parameters for zone transfers and caching. The serial number is incremented each time the zone is updated, which triggers secondary nameservers to refresh their copies. SOA records are critical for DNS zone management and debugging propagation issues.

PTR Records

PTR (Pointer) records provide reverse DNS lookup, mapping an IP address back to a domain name. They are stored in special in-addr.arpa (IPv4) or ip6.arpa (IPv6) zones. Reverse DNS is used for email server verification (many mail servers reject messages from IPs without valid PTR records), network diagnostics, logging, and security investigations.

How This Tool Works

This DNS lookup tool runs entirely in your browser. Queries are sent directly from your browser to Google's DNS-over-HTTPS (DoH) endpoint at dns.google/resolve. DoH encrypts DNS queries over HTTPS, preventing network intermediaries from seeing or modifying your DNS lookups. No data passes through SecureBin servers. The results show record type, TTL (Time To Live in seconds), and the record data for each DNS response.