Domain names are the front door to applications deployed on Scalingo. They allow teams to expose services under clear, stable and branded addresses, thus turning technical endpoints into polished, customer-ready experiences.

While Scalingo seamlessly handles routing, security, TLS, and scalability behind the scenes, domains let you focus on delivering a reliable presence on the Internet.

Domain Names at Scalingo

At Scalingo, we offer two main services related to domain names:

• Each application deployed on Scalingo is assigned a default domain name, ending in scalingo.io, allowing public access to the app.
• We also support custom domain names, for a fully personalized experience.

Understanding Domain Names

To help you better understand domain names, we think it’s better to start with a few definitions:

Domain Name

A domain name is a human-readable address used by people to find a website or service on the Internet. It allows humans to type example.com instead of an hard-to-remember IP address, such as 198.51.100.27.

Registrar

Domain names can be reserved for a few months (sometimes years) from companies called registrars.

Zone File

A domain name is configured via its zone file. A zone file is a text file that describes a DNS zone. It contains mappings between domain names and resources (such as IP addresses). These mappings are called resource records (RR). The registrar from which you have purchased the domain name usually provides an interface to edit the corresponding zone file.

Results of a zone file update can take time to be fully propagated worldwide, so please plan your updates accordingly!

Apex Domain

An apex domain is the main, highest-level domain name that one can own, without any subdomains in front of it.

For instance, example.com. is an apex domain. It’s made of a Top-Level Domain (TLD): .com. and a Second-Level Domain (SLD): example.

Wildcard Domain

A wildcard domain is a domain configuration that automatically matches any subdomain that doesn’t already have a specific record. They use an asterisk (*) as a placeholder.

For instance, *.example.com is a wildcard domain, matching www.example.com, shop.example.com, app.example.com, or anything.example.com.

Canonical Domain

A canonical domain is the single, preferred version of a domain name that you choose to represent your website or service when multiple domains or subdomains point to the same content.

For instance, example.com, www.example.com, and app.example.com may point to the very same application. Setting the canonical domain to www.example.com tells everyone that this is the one true version, and helps search engines avoid duplicate content.