Builder Toolkit · 08 / 11

Domains and DNS

Understand what a domain is, what A and CNAME records do, and how to point a domain at your deployment.

Domains and DNS

What this is

A domain is the readable address people type, such as mycafe.com.

DNS is the lookup system that turns that name into the actual server address. It is the phone book of the internet.

The one idea

Buying a domain does not connect it to anything. DNS records are what point the name at your deployment.

Why it matters

Your host gives you a working URL for free. A custom domain is not required to ship, and chasing one too early is a common way to lose a session.

It matters when the project becomes real: a business, a portfolio, something you hand to a client. It is also where beginners lose hours, usually by expecting an instant result from a system designed to be cached.

What to do

Learn the two records you will actually use

Record	Points a name at	Typical use
A	An IP address, like `76.76.21.21`	The bare domain, `example.com`
CNAME	Another domain name	A subdomain, like `www.example.com`

There are many other record types. For pointing a domain at a deployment, these two cover nearly every case.

Connect a domain

Buy the domain from a registrar. Any reputable one works.
In your hosting project settings, add the custom domain.
Your host shows you the exact records to create. Copy them precisely.
In your registrar's DNS settings, create those records.
Wait. Then check.

Always use the values your host displays. Do not copy an IP address out of a tutorial, including this one. Hosts change them.

Propagation is not instant

DNS changes are cached across the internet. Updates commonly appear within minutes but can take up to 24 to 48 hours. Repeatedly changing the record because nothing happened yet resets your own progress.

Understand HTTPS

Once DNS resolves, your host will normally issue an HTTPS certificate automatically, so your site loads with a padlock.

If the certificate fails to issue, the usual cause is a DNS record that is still wrong or not yet visible. Fix DNS first. The certificate follows.

Do this now

Only if you own a domain: open your registrar's DNS screen and find where records are listed. Just locate it. Do not change anything yet.

Check yourself

I can explain the difference between an A record and a CNAME.
I know my host supplies the exact record values.
I know DNS changes can take hours, not seconds.
I know a free hosting URL is enough to ship and share proof.

If the domain still does not resolve

Confirm you edited DNS at the service that currently controls the domain. If you changed nameservers, your registrar's DNS screen may no longer be the one in use, and edits there do nothing.

Common mistakes

Buying a domain and expecting it to work with no records set.
Copying an IP address from a tutorial instead of from your host.
Changing records every few minutes because the site has not appeared yet.
Editing DNS at the wrong provider after moving nameservers.
Adding the bare domain but forgetting www, so half of visitors hit nothing.
Treating a custom domain as a requirement for finishing a build. It is not.

Next step

Address sorted. Before you share the link, run the checks in Deployment QA.