# Setting up automatic subdomains for an Amazon Route 53 custom domain
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After an app is connected to a custom domain in Route 53, Amplify enables you to automatically create subdomains for newly connected branches. For example, if you connect your **dev** branch, Amplify can automatically create **dev.exampledomain.com**. When you delete a branch, any associated subdomains are automatically deleted. 

**To set up automatic subdomain creation for newly connected branches**

1. Sign in to the AWS Management Console and open the [Amplify console](https://console.aws.amazon.com/amplify/).

1. Choose an app that is connected to a custom domain managed in Route 53.

1. In the navigation pane, choose **Hosting**, and then choose **Custom domains**.

1. On the **Custom domains** page, choose **Domain configuration**.

1. In the **Automatic subdomain creation** section, turn on the feature.

**Note**  
This feature is available only for root domains, for example, **exampledomain.com**. The Amplify console doesn't display this check box if your domain is already a subdomain, such as ** dev.exampledomain.com**.

## Web previews with subdomains
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After you enable **Automatic subdomain creation** using the preceding instructions, your app’s pull request web previews will also be accessible with automatically created subdomains. When a pull request is closed, the associated branch and subdomain are automatically deleted. For more information on setting up web previews for pull requests, see [Web previews for pull requests](pr-previews.md).