Use the WHOISDR free DNS lookup tool to check the Domain Name System records associated with any domain name. Enter a domain above to inspect available DNS information, including A, AAAA, MX, NS, TXT, CNAME, and SOA records. DNS lookups can help you investigate where a website points, identify its mail servers, verify nameservers, troubleshoot configuration problems, and understand how a domain is connected to services across the Internet.

WHOISDR makes DNS research easier by bringing important domain records together in one convenient lookup. Whether you are a website owner, developer, system administrator, cybersecurity researcher, marketer, or simply trying to diagnose why a domain is not working correctly, you can use this page as a starting point for investigating its DNS configuration.

Need registration information instead? Use our WHOIS Lookup Tool to check available domain registration dates, registrar information, domain status, nameservers, and other registration data.

What Is a DNS Lookup?

A DNS lookup retrieves Domain Name System records associated with a domain or hostname. DNS is the distributed system that helps translate human-readable domain names into information computers and Internet services can use.

When you type a domain name into a browser, your device ultimately needs information about where that domain should be reached. DNS provides this information through different types of records. Some records point a hostname to an IPv4 or IPv6 address, while others specify mail servers, authoritative nameservers, aliases, verification values, and other configuration information.

A DNS checker allows you to inspect these records without manually querying DNS servers from a command line.

What DNS Records Can You Check?

Different DNS record types serve different purposes. Understanding the most common records makes it much easier to diagnose website, email, and domain configuration problems.

A Record Lookup

An A record maps a hostname to an IPv4 address. For example, a domain's A record may point its root hostname to the IPv4 address of the server or infrastructure serving the website.

An A record lookup is useful when you want to determine which IPv4 address a hostname currently resolves to or verify that a recent DNS change is returning the intended address.

AAAA Record Lookup

An AAAA record performs a similar role to an A record but points a hostname to an IPv6 address. Websites and services that support IPv6 may publish AAAA records alongside their IPv4 A records.

If a website behaves differently over IPv4 and IPv6, checking both record types can provide useful troubleshooting information.

MX Record Lookup

An MX record, or Mail Exchange record, identifies mail servers responsible for receiving email for a domain.

MX records usually include a preference or priority value. When multiple mail servers are listed, these values help sending mail systems determine which server should be attempted first.

An MX lookup can be useful when configuring business email, migrating between email providers, diagnosing email delivery problems, or confirming that a domain points to the expected mail service.

NS Record Lookup

NS records identify the authoritative nameservers responsible for a domain's DNS zone. These servers provide authoritative answers about the DNS records configured for the domain.

Checking NS records can help determine which DNS provider appears to manage a domain's authoritative DNS and whether nameserver changes are reflected in DNS.

TXT Record Lookup

TXT records allow domain administrators to publish text-based values in DNS. They are widely used for domain verification, email authentication, security policies, and service configuration.

TXT records may contain information related to technologies such as SPF, DKIM, DMARC, and third-party domain verification. Because one domain can have multiple TXT records, it is important to inspect the complete set returned by a lookup.

CNAME Record Lookup

A CNAME record creates an alias from one hostname to another hostname. Instead of pointing directly to an IP address, the alias points toward another DNS name.

CNAME records are frequently used for subdomains and services provided through external platforms, content delivery systems, hosted applications, and other infrastructure.

SOA Record Lookup

The SOA record, or Start of Authority record, contains administrative information about a DNS zone. Depending on the response, it can include information such as the primary nameserver, responsible-party field, zone serial number, refresh interval, retry interval, expiration value, and negative caching parameters.

SOA information can be especially useful to administrators troubleshooting authoritative DNS configurations.

How to Use the WHOISDR DNS Checker

Checking DNS records with WHOISDR is straightforward:

1. Enter a domain name into the search box above.
2. Select the DNS lookup option you want to perform when record-type selection is available.
3. Click Check to run the query.
4. Review the returned DNS records and compare them with the configuration you expect.
5. Run additional record lookups when you need a more complete picture of the domain.

For example, if you are troubleshooting a website, you may want to examine its A, AAAA, CNAME, and NS records. If you are troubleshooting email, MX and TXT records may be particularly important.

DNS Lookup vs. WHOIS Lookup

DNS and WHOIS both provide useful information about a domain, but they serve different purposes.

DNS records describe technical configuration. They can tell you where a hostname resolves, which servers handle email, which nameservers are authoritative, and which verification or policy values have been published.

WHOIS registration data describes aspects of the domain registration. Depending on what information is publicly available, WHOIS may show the registrar, registration date, expiration date, nameservers, domain status codes, and other registration information.

Think of the difference this way:

• WHOIS: Who manages the registration and what is its registration status?
• DNS: How is the domain technically configured to work on the Internet?

For more complete domain research, use both the WHOIS Lookup Tool and this DNS checker.

How DNS Works

The Domain Name System is often described as a directory for the Internet, but the actual process is more sophisticated. DNS is distributed across many servers rather than being maintained in one central database.

When a user requests a domain, a DNS resolver attempts to obtain the records necessary to answer that request. If the information is not already cached, the resolution process can involve DNS infrastructure at several levels before reaching servers authoritative for the requested domain.

The resulting information can then be cached for a period determined in part by DNS configuration. This is one reason DNS changes may not appear identically everywhere immediately after an administrator modifies a record.

What Is DNS Propagation?

The phrase DNS propagation is commonly used to describe the period during which users and recursive resolvers may receive different results after DNS records have changed.

DNS does not literally send every change instantly to every resolver on the Internet. Instead, DNS information is cached. Cached answers can continue to be used until their applicable cache lifetime expires, after which a resolver can obtain updated information.

Because different resolvers may have cached a previous record at different times, DNS changes can appear inconsistent temporarily.

What Is DNS TTL?

TTL means Time to Live. A DNS record's TTL helps determine how long DNS information may be cached before a resolver should obtain a newer answer.

TTL values are expressed in seconds. For example, a TTL of 3600 corresponds to one hour. However, actual DNS behavior can involve multiple caching layers, so troubleshooting should consider more than the configured TTL alone.

Administrators sometimes lower TTL values before a planned migration so cached records can expire more quickly. After the migration is complete and stable, TTL values may be increased again according to operational needs.

How to Find the IP Address of a Domain

If you want to determine which IP address a hostname resolves to, check its A records for IPv4 and AAAA records for IPv6.

Keep in mind that the returned IP address does not always identify a single physical web server. Modern websites frequently use content delivery networks, reverse proxies, cloud infrastructure, load balancers, and distributed hosting systems.

A domain may also return multiple IP addresses.

How to Find a Domain's Mail Server

To investigate where a domain receives email, perform an MX record lookup. The returned MX records identify hostnames designated to receive mail for that domain.

If multiple MX records exist, examine their preference values as well as their hostnames. Lower numerical preference values are generally given higher priority.

MX records are only part of an email configuration. TXT records may also contain important email-related policies and authentication information.

How to Check a Domain's Nameservers

Use an NS lookup to retrieve nameserver records for a domain. These records identify authoritative DNS servers associated with the domain's DNS zone.

You may also encounter nameserver information in WHOIS results. Comparing registration-related nameserver information with DNS results can sometimes be useful during troubleshooting.

DNS Records and Email Authentication

DNS plays an important role in modern email authentication. Domain owners can publish policies and verification information that receiving mail systems use when evaluating messages.

SPF

SPF information is generally published through a TXT record. It can identify systems authorized by a domain's SPF policy to send email on its behalf.

DKIM

DKIM uses cryptographic signatures to help receiving systems verify that certain email content was signed using a key associated with the sending domain. DKIM public-key information is published in DNS under selector-specific hostnames.

DMARC

DMARC builds on SPF and DKIM and allows domain owners to publish policy and reporting information. DMARC records are typically stored as TXT records beneath the _dmarc hostname.

Inspecting TXT records can therefore be an important part of troubleshooting email authentication, although interpreting SPF, DKIM, and DMARC correctly requires examining the relevant record names and policies.

Common DNS Problems

Domain Points to the Wrong IP Address

An outdated or incorrectly configured A or AAAA record can send users toward the wrong infrastructure. Compare the current DNS result with the address your hosting provider expects.

Website Works for Some People but Not Others

This can occur after DNS changes when different resolvers still have different cached information. It can also have causes unrelated to DNS, so DNS results should be considered as part of a broader troubleshooting process.

Email Is Not Being Delivered Correctly

Check the domain's MX records and relevant TXT records. Incorrect mail-server destinations or email authentication configurations can contribute to email problems.

Subdomain Does Not Work

Check whether the subdomain has the expected A, AAAA, or CNAME record. A configuration error, missing record, or unexpected alias can prevent a hostname from resolving as intended.

Nameserver Changes Are Not Appearing

Verify the domain's authoritative nameserver configuration and allow for caching and delegation changes. Comparing DNS information with the domain's registration information may provide additional context.

Why Do DNS Results Sometimes Change?

DNS results are not necessarily permanent. Domain administrators can modify records, hosting providers can change infrastructure, load-balanced services can return multiple addresses, and cached records eventually expire.

Some large websites deliberately return different DNS answers depending on network conditions, geography, availability, or infrastructure design. Therefore, a DNS result represents information obtained for a particular query rather than a guarantee that the same answer will remain unchanged indefinitely.

DNS Lookup FAQ

Is the WHOISDR DNS lookup free?

WHOISDR provides a web-based DNS lookup tool that lets you investigate available DNS records directly from your browser.

Can I find a website's IP address with DNS?

You can check A and AAAA records to see which IPv4 and IPv6 addresses a hostname currently resolves to. The returned addresses may belong to hosting infrastructure, a CDN, reverse proxy, load balancer, or another intermediary rather than a single physical server.

Which DNS record controls email?

MX records identify mail exchangers responsible for receiving email for a domain. TXT records are also important because they can contain email-authentication information such as SPF and DMARC-related policies.

Which DNS record points a domain to a website?

A and AAAA records commonly map hostnames to IPv4 and IPv6 addresses. CNAME records can instead alias one hostname to another hostname. The precise configuration depends on how the website is hosted.

What does an NS record tell me?

NS records identify authoritative nameservers for a DNS zone. They can help determine which nameservers are responsible for answering authoritative DNS queries for the domain.

What does a TXT record do?

TXT records store text-based information in DNS. They are commonly used for domain verification, SPF, DMARC, and configuration requirements for third-party services.

How long do DNS changes take?

There is no single universal waiting period. DNS caching, TTL values, delegation changes, recursive resolvers, and the type of configuration change can all affect when updated information is observed.

Can a domain have multiple A or MX records?

Yes. Domains can have multiple records of the same type. Multiple A records may be used as part of distributed infrastructure, while multiple MX records can provide prioritized mail-server destinations.

Does DNS show who owns a domain?

No. DNS primarily describes technical configuration. To research publicly available registration information, use the WHOIS Lookup Tool.

Why does my DNS lookup return no record?

A missing result does not necessarily mean the entire domain is unavailable. The specific record type or hostname queried may simply have no applicable record, or the configuration may use another DNS mechanism.

Check Your Domain's DNS Records

DNS records are fundamental to how websites, email systems, applications, and other Internet services locate and communicate with one another. Understanding those records can make domain research and troubleshooting considerably easier.

Enter a domain into the DNS checker above to begin. Examine its IP-related records, mail servers, nameservers, aliases, and other available DNS information. For registration-related research, follow up with a WHOIS search.

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