Zero-Downtime Domain Migration with Vercel

Migrate your domain from an external service to Vercel with no downtime, in just a few steps.

When migrating to another set of nameservers, there can often be downtime incurred. In this guide we will walk you through adding your domain to Vercel and setting it up before migrating the nameservers, ensuring no downtime at any point.

Warning: We strongly advise against using external verification as it prevents you from receiving the full benefits of Vercel's platform and services, such as the automatic renewal of wildcard certificates. Furthermore, many DNS providers do not have a global connection capable of low-latency geo-routing, which is likely to slow down your apps.

Step 1: Adding and Verifying Your Domain

To get the process started, you will need to add your domain to your account or team by using the following command:

vercel domains add <domain>

Adding a domain to a Vercel account using Vercel CLI.

This command will add the domain to your account and output information you will need in order to verify the domain is yours.

You will receive two options:

  • Verify with Nameservers
  • Verify with TXT record

Adding a domain with Vercel CLI.

To avoid pointing the nameservers to Vercel prematurely, use the TXT method for verification.

With your domain provider, create the TXT record using the name (also known as host or alias) _now and the value provided when adding the domain.

Note: If you have forgotten or misplaced the value before verifying the domain, you can use vercel domains inspect domain to retrieve the verification methods and value again.

Vercel periodically checks for whether or not the TXT record (or nameservers in another case) has been added and then mark the domain as verified when it detects them. You can force Vercel to check for the verification by using the following command:

vercel domains verify <domain>

Verifying a domain with Vercel CLI.

Step 2: Preparing the Domain with DNS, Certs, and Deploying to Production

Now that your domain is verified, you have more control over it with Vercel. You can now generate an SSL Certificate, add any DNS Records, and deploy your app using your domain, all ready for when you switch over fully.

Generating an SSL Certificate

With Vercel CLI, you can generate an SSL certificate for your domain and all subdomains, called common names (CNs), with the following command:

vercel certs issue \*.<domain> <domain> --challenge-only

Generating an SSL certificate for a domain and all subdomains with Vercel CLI.

You will then be asked to solve a DNS challenge, required for the Certificate Authority (CA) to prove that Vercel has sufficient permissions, consisting of two TXT records.

Once these TXT records are added to your domain via your domain provider, run the vercel certs issue *.<domain> <domain> command again to attempt the certificate issuance.

Adding DNS Records

The next step is to add any DNS records your domain might have had before. For example, MX records.

In this example, we'll take Gmail's current MX records and add them with Vercel CLI:

vercel dns add <domain> @ MX ASPMX.L.GOOGLE.COM 1 && vercel dns add <domain> @ MX ALT1.ASPMX.L.GOOGLE.COM 5 && vercel dns add <domain> @ MX ALT2.ASPMX.L.GOOGLE.COM 5 && vercel dns add <domain> @ MX ALT3.ASPMX.L.GOOGLE.COM 10 && vercel dns add <domain> @ MX ALT4.ASPMX.L.GOOGLE.COM 10

Adding MX records to a domain with Vercel CLI.

The above demonstrates using the vercel dns add command to add multiple MX record to your domain.

Deploying with Your Custom Domain

To use your custom domain with your project, you can add it to your project from the Domains section of the project dashboard.

Note: A project is defined when first deploying (using the directory name), or when creating a project from your dashboard. You can read more about them in the projects documentation.

Select a project from your dashboard and click the Domains tab. Add your custom domain for production here, such as [custom domain name].[tld], a subdomain [subdomain].[custom domain name].[tld] (providing the root domain is added to your account), or using the free now.sh deployment suffix [name].now.sh.

If the domain is registered to your account and available for use it will be indicated below the input box and you can continue. Otherwise, if the domain is not registered to your account, it will automatically be added and we will attempt to verify it for you.

When the domain is verified, you can deploy your project to production with Vercel CLI:

vercel --prod

Deploying a project to production with Vercel CLI.

Note: Your projects will automatically use your custom domain when merging or pushing to the default branch when using either Vercel for GitHub,Vercel for GitLab, orVercel for Bitbucket.

Now, your domain will be pointing to your latest deployment and you're are ready to move your nameservers across to show that deployment.

Step 3: Moving the Nameservers

Once your domain is set up correctly and contains all you need for a successful migration, you will be free to change the nameservers of your domain to point to Vercel DNS via your domain provider.

Using vercel domains inspect <domain>, you can find your intended set of nameservers to use with your domain, in case you have forgotten them when you first added the domain.

Once the nameservers have been added and propagation is complete, your domain will successfully point to your deployment from your domain, which includes a free SSL certificate and any DNS records you setup!



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Written by mcsdevmcsdev