Replace "pantheonsite.io" within Pantheon environments by adding a custom vanity domain.
Pantheon Partners, Strategic Partners, Enterprise accounts, Resellers, and OEM Partners have the ability to provision a custom vanity domain for each environment on every site running on the platform, in addition to the default Platform domain (
The Vanity domain can either be a subdomain of your primary site (
sites.mydomain.com) or a dedicated domain name (
If a subdomain of your primary site is configured, a newly created site named "supersite" will then have a Dev environment URL of
dev-supersite.sites.mydomain.com. If a dedicated domain name is used, the site would instead have a Dev environment URL of
Request the Vanity Domain
From your Organization Dashboard, go to Dashboard and submit a support request with "Request for custom Vanity domain" as the subject. You must provide the Vanity domain required on the site, like
We recommend using a separate domain from your production site. This prevents any security issues related to domain-specific cookies. Even the same domain under a different TLD (
.net, etc) would suffice.
Create a Wildcard CNAME Record
At your DNS provider, create a wildcard CNAME record pointing to our edge. If you go with
sites.example.com, the record would need to be created as follows:
Effects and Considerations
Existing sites created before configuring a Vanity domain will continue to use the default Platform domains and will not use the custom Vanity domain.
Sites associated with your organization will receive the custom Vanity domain for all environments (including Multidev) created while the organization remains a supporting organization.
After adding a custom Vanity domain to your organization, some workflow operations such as restoring an environment from a backup or changing the PHP version, can cause site domain URLs in other environments to unexpectedly change from the Pantheon domain to the custom domain.
Environment URLs are permanent. If an organization is removed as the supporting organization, any environment created during its association will keep the original URL after removal. Paid sites can add custom domains to any environment, as a workaround for those wishing to use different URLs after launch and disassociation of the site with the organization.
Do not configure DNS for custom domains using Vanity domain values. Even after configuring a vanity domain, your custom domain CNAME records should always point to the platform domain values, as recommended within the Domains / HTTPS page. Vanity domains are designed to be viewed by end users, not added into records for other domains.
Incorrect DNS Configuration
Correct DNS Configuration
If you run sites on subdomains of your primary site (e.g.
sites.awesomeagency.com), you should be aware of some security considerations:
- The sites on the subdomains may be able to read cookies set on your primary site.
- If a site on the subdomain is reported as a malicious phishing/spam/malware site, it could prevent access to your main marketing site if Google/Norton/etc. block the site.
- HTTPS is not provisioned for vanity domains. Only custom domains will have HTTPS provisioned.
Robots.txt with Custom Vanity Domains
For SEO and to prevent duplicate content, the robots.txt file attached to the custom Vanity domain will contain the following by default:
# https://live-sitename.agencyname.com/robots.txt User-agent: * Disallow: /
To present an alternate robots.txt file from within the source code, a custom domain needs to be added to the site's Dashboard and the appropriate DNS record created.