Are Vercel Preview Deployments indexed by search engines?

For SEO purposes, it's necessary to ensure that your website is not serving duplicate content. It is important to ensure you are not hosting the same content at more than a single URL.

Given the nature of Preview Deployments, and the way they are designed to give a realistic representation of a Production Deployment, they serve duplicate content by default. This article outlines how this case is handled by Vercel, to ensure your SEO ranking is not negatively impacted by duplicate content.

X-Robots-Tag Header

Vercel Preview Deployments will not be indexed by search engines because the X-Robots-Tag HTTP header will be set to noindex. To confirm this, you can use the following curl (already available on most desktop devices) command in your terminal to check your Preview Deployment's headers:

curl -I <preview-deployment-url>

Using the curl command to check your Preview Deployment's headers.

Amongst the output, you will find an X-Robots-Tag header after executing the curl command.

x-robots-tag: noindex

Verifying your Preview Deployment's headers using the terminal.

Note:

If a Custom Domain is assigned to a non-Production Branch, it will not set the X-Robots-Tag: noindex header.

Contacting Vercel Support

If you believe your Preview Deployment is not showing the correct header, please contact Vercel Support using the support form available from the Vercel dashboard.

Updated January 11th 2021