A root domain is the base level of a domain name: the combination of the second-level domain and TLD without any subdomain prefix. example.com is a root domain. google.com is a root domain. redirect.supply is a root domain. Any subdomain added to the left, www.example.com, blog.example.com, app.redirect.supply: is built on top of the root domain but is not itself a root domain.

Root domain and apex domain refer to the same concept and the terms are used interchangeably in most contexts. Both describe the domain at its base level, the registered domain name without any prefix. Some technical contexts favour apex domain, particularly when discussing DNS zone structure and the CNAME restriction. Some marketing and SEO contexts favour root domain, particularly when discussing domain authority, backlinks, and brand identity. The underlying concept is identical.

The root domain is the fundamental unit of domain registration, ownership, and SEO equity. It is what is registered with a domain registrar. It is what SSL certificates are issued for. It is what DNS zones are organised around. And it is what search engines measure domain authority against, the accumulated link juice and ranking signals associated with all pages and subdomains under a root domain are consolidated in that root domain’s authority profile.

Root domain vs apex domain vs naked domain

Three terms are used to describe the base domain without subdomains, root domain, apex domain, and naked domain. Understanding when each is used clarifies the different contexts in which this concept appears.

Root domain: the most commonly used general term. Used in SEO, marketing, and general web discussions to refer to the registered base domain. example.com is the root domain from which www.example.com, blog.example.com, and all other subdomains extend. In SEO tools and analytics platforms this term typically refers to the domain at this base level.

Apex domain: the technically preferred term in DNS contexts. Used specifically when discussing DNS zone structure, the CNAME restriction at the zone apex, and DNS record configuration. The apex is the point at the top of the DNS zone where SOA records and NS records must exist.

Naked domain: an informal term emphasising the absence of any prefix, particularly the absence of www. Saying a domain is the naked domain is another way of saying it is the apex without the www subdomain. Less common in technical documentation than root domain or apex domain but occasionally used in web development and hosting contexts.

All three terms describe the same thing, example.com without any prefix. The appropriate term depends on context. DNS configuration discussions use apex. SEO discussions use root domain. Casual web development discussions may use any of the three.

How root domains relate to subdomains

The root domain is the parent of all subdomains under it. Every subdomain is built by adding one or more labels to the left of the root domain, www.example.com, shop.example.com, api.v2.example.com. The root domain controls the DNS zone that contains records for all these subdomains.

From a DNS perspective the root domain’s zone is the container. The zone holds A records, CNAME records, MX records, TXT records, and all other record types for both the root domain itself and all subdomains within it, unless specific subdomains are delegated to separate zones through NS records.

Adding a subdomain requires only adding DNS records in the root domain’s zone. Creating shop.example.com means adding a CNAME or A record for shop in the example.com zone. No separate registration is needed. No additional cost beyond the root domain registration. The root domain registration covers all subdomains beneath it.

Delegating a subdomain, creating a separate DNS zone for it, requires adding NS records for the subdomain in the root domain’s zone and configuring the subdomain zone on the delegated nameservers. This is typically done when different teams or services need independent control over a subdomain’s DNS. The root domain zone retains authority over everything except the delegated subdomain.

Root domain authority in SEO

In SEO contexts the root domain is the unit at which domain authority, the accumulated ranking power of all backlinks and signals from across the domain, is measured and reported. Understanding root domain authority clarifies how SEO equity flows through domain and subdomain structures.

Domain authority consolidation: backlinks pointing to any URL under a root domain, example.com/page, www.example.com/post, blog.example.com/article: all contribute to the root domain’s authority profile. SEO tools like Ahrefs and Moz measure domain authority at the root domain level because the root domain is the registered unit of ownership and the level at which search engines primarily assess authority.

Subdomain authority: subdomains can develop their own authority separate from the root domain in some SEO frameworks, particularly when the subdomain hosts substantially different content. Google has stated that subdomains are treated as separate from the root domain in some contexts while being associated with it in others. For most practical purposes backlinks to subdomains contribute positively to the overall domain’s authority profile.

Root domain changes and authority: when a root domain changes, through rebranding or domain migration: the accumulated authority of the old root domain can be transferred to the new one through 301 permanent redirects. A complete migration with correct permanent redirects from every URL on the old domain to its equivalent on the new domain transfers as much of the accumulated authority as possible. This is why maintaining the old domain and its redirects is important for the SEO health of the new domain.

Root domain and redirect management

Root domain management is central to redirect management, most significant redirect scenarios involve the root domain as either the redirect source or the redirect destination.

Redirecting the root domain to www: one of the most universal redirect configurations. Visitors who type example.com without www are permanently redirected to www.example.com. The root domain serves only as a redirect trigger, all content is hosted at www. Connecting the root domain to redirect infrastructure requires addressing the CNAME restriction through A records, ALIAS records, or Cloudflare CNAME flattening.

Redirecting www to the root domain: the opposite configuration, increasingly common as the www prefix has become less standard for many modern websites. Visitors typing www.example.com are permanently redirected to example.com. The root domain hosts all content. The www subdomain is a redirect trigger.

Domain migration from old root domain: when a root domain is retired and replaced by a new one permanent redirects from the old root domain to the new preserve SEO equity and user experience. Every URL pattern on the old root domain needs a redirect to its equivalent on the new root domain. The old root domain registration must be maintained as long as redirects are needed.

Brand protection root domains: organisations register multiple root domains, common misspellings, alternative TLDs, related names, and redirect them all to the primary root domain. Each brand protection domain needs its own DNS configuration and redirect rule despite all pointing to the same destination. Centralised redirect management handles multiple root domains efficiently.

Root domain as redirect destination: many redirects lead to the root domain homepage as a fallback redirect. When no specific path-level rule matches an incoming request the fallback sends visitors to the root domain, https://example.com: rather than leaving them on a 404. The root domain must be fully accessible and returning 200 OK for fallback redirects to function correctly.

Root domain DNS configuration

Configuring DNS for a root domain involves specific record types that differ from subdomain configuration due to the CNAME restriction and the requirement for zone-defining records.

Required records at the zone apex: every root domain zone must have NS records: specifying the authoritative nameservers, and an SOA record: containing administrative zone information. These are created automatically by DNS providers when a zone is set up. They cannot be deleted and cannot coexist with CNAME records.

A records for the root domain: connecting the root domain to web infrastructure, whether hosting, redirect management, or any other service, typically uses A records pointing to the service’s IP addresses. Unlike subdomains that use CNAME records root domains use A records because of the CNAME restriction.

MX records for email: MX records at the root domain specify the mail servers for the domain. Email addressed to any address @example.com is routed by these records. MX records coexist with A records at the root domain without conflict.

TXT records for verification and authentication: TXT records at the root domain serve multiple purposes, domain ownership verification for services like Google Search Console, SPF records for email authentication, and DMARC policies. Multiple TXT records can coexist at the root domain.

ALIAS/ANAME records: some DNS providers offer ALIAS or ANAME records at the root domain that provide CNAME-like behaviour, following a hostname to its current IP address automatically while remaining compatible with the DNS zone requirements. These are the preferred connection method when both the DNS provider supports them and the redirect infrastructure provides a hostname rather than a fixed IP.

Root domain vs URL path

A common confusion in web and SEO discussions is between the root domain and the root path or homepage URL. These are related but distinct concepts.

Root domain: example.com. The registered base domain name, the DNS addressable unit. No path component.

Root path or homepage: https://example.com/ or https://www.example.com/. A complete URL including protocol, domain, and the root path /. The homepage URL includes the root domain but also specifies the protocol, subdomain, and path.

When SEO tools and discussions refer to domain authority they mean the root domain, the complete authority profile of all pages and backlinks under example.com regardless of subdomain or path. When a redirect rule points to the homepage it points to the complete URL https://example.com/: specifying all URL components including the path.

This distinction matters for redirect configuration. A redirect destination of https://example.com and https://example.com/: with and without the trailing slash, may behave differently depending on server configuration. The server at example.com may serve the same homepage for both or may redirect one to the other. Redirect destinations should be tested to confirm they resolve to 200 OK rather than triggering further redirects.

Root domain registration and ownership

The root domain is the unit of registration, the entity that is purchased from a registrar and owned for a registration period. Understanding root domain registration is essential for maintaining control of a domain and the redirect infrastructure built on it.

Registration period: domains are registered for one to ten years. At expiry the domain must be renewed to maintain ownership. Many registrars offer automatic renewal, charged to the registrant’s payment method before expiry. Manual renewal requires monitoring expiry dates and renewing before the domain enters the grace period.

Expired domains and redirects: if a root domain used for redirects expires the redirects stop working immediately when the domain is released. Visitors following links to the expired domain receive DNS errors rather than being redirected. Recovering an expired domain, through the grace period or by re-registering after release, may be possible but is not guaranteed. Monitoring root domain expiry dates for all domains involved in redirect configurations is essential.

Transfer locks: registrars apply transfer locks that prevent domain transfers for a period after registration changes. Understanding transfer lock policies is important when planning to move domains between registrars, for example when migrating DNS to a new provider requires transferring registration.

WHOIS and ownership verification: some services verify root domain ownership through WHOIS records or DNS-based verification before activating features. The contact information in WHOIS must be accurate and the domain owner must control the DNS zone for verification to succeed.