A domain name is the web address or URL used to visit your site. The Domain Name System (DNS) resolves human-readable names like
www.example.com into machine-readable IP addresses like 127.0.0.1. All Pantheon sites are accessible via platform domains, and you can easily connect your own custom domain to paid sites.
Optimize your dev team and streamline internal workflows. Pantheon delivers custom workshops to help development teams master our platform and improve their internal DevOps
Pantheon issues platform domains for all environments. Each environment (Dev, Test, Live, each Multidev) is accessible via the platform domain, matching the following patterns:
All platform domains are available over HTTPS. Redirecting to HTTPS during development and testing is a good best practice to ensure you are ready to go live with HTTPS. See Redirect to HTTPS for more information.
Pantheon serves a default robots.txt that disallows crawlers on platform domains (
/*.sites.my-agency.com). Crawlers are allowed on the Live environment for requests served with a custom domain (e.g.,
www.example.com). If you attempt to access your Live environment with a platform domain, even if you have a domain associated with the environment, the default robots.txt will be served.
Pantheon does not allow crawlers on Dev, Test, or Multidev environments. Adding a custom domain to an environment other than Live will not permit crawlers to that environment.
If you don't already own a domain name, register one with a third-party provider. Pantheon is not a domain registrar, but we've created documentation for several popular DNS managers:
Connect your custom domain on the Site Dashboard, and point DNS at Pantheon to trigger automated HTTPS provisioning.
A paid plan is required to connect custom domains to your site, up to the following limits:
|Basic||Performance S||Performance M||Performance L||Performance XL||Elite|
|Custom Domain Limit (per site)||5||10||15||35||70||270|
|Free and managed HTTPS||✓||✓||✓||✓||✓||✓|
Add all domains (example.com and www.example.com are different domains!) you want to resolve to Pantheon within the Site Dashboard, for each respective environment, as described in Launch Essentials. Automatic resolution of domains and wildcards are not supported.
In September 2017, Google announced that is was planning to make HSTS preloading mandatory for the Top-Level Domains (TLDs) available exclusively through Google Registry. That means that, moving forward, some TLDs will automatically redirect to HTTPS, and will be unable to load insecure sites or site pages. When selecting a domain to use as a custom or vanity domain, it's important to note the 45 TLDs that are subject to mandatory HSTS preloading:
.gle .prod .docs .cal .soy .how .chrome .ads .mov .youtube .channel .nexus .goog .boo .dad .drive .hangout .new .eat .app .moto .ing .meme .here .zip .guge .car .foo .day .dev .play .gmail .fly .gbiz .rsvp .android .map .page .google .dclk .search .prof .phd .esq .みんな .谷歌 .グーグル
When using one of the above domains as a vanity domain, keep in mind that every environment domain must have HTTPS provisioned or that environment's domain will be inaccessible. Because Pantheon doesn't provision HTTPS for vanity domains, this will need to be set up and managed using a custom certificate. You should also keep in mind that any Multidev environments created using a secure only TLD will need to have HTTPS provisioned before the site domain will work.
When using one of the above TLDs as a custom domain for your site, Pantheon will provision the necessary certificates if you are using Pantheon's automated Global CDN. If the site is using a custom certificate, then each custom domain needs to have the certificate provisioned by the 3rd party used to manage HTTPS for the site.
From your site dashboard, for the environment you want the domain to point to (usually Live), click on the Domains / HTTPS tab.
If no domains have been added yet, click Connect Live Domain:
If one (or more) domains have already been added, click Connect Domain:
Enter the domain you'd like to add in the "Enter domain to connect" field, then click Connect Domain:
After adding your domain, you'll be automatically taken to the domain's "Details" page where you will see both the current DNS records detected (the "Detected Values"), as well as the values to be added at your DNS host ("Required Values"):
Add the values to your DNS management service. For more details, see Introduction to Domain Name Services.
Pantheon uses the term primary domain to refer to a single domain used to serve all traffic from a site. For example, configuring
www.example.com as the primary domain means that requests to
example.com (or any other domain connected to the environment) all get redirected to
www.example.com. This assumes that you have added both
www.example.com to the Site Dashboard.
Redirecting all traffic to a primary domain is a best practice for SEO since it avoids duplicate content. It also prevents session strangeness, where a user can be logged in to one domain but logged out of other domains at the same time, and it can make it easier to measure and monitor website traffic.
For more redirect scenarios, see Configure Redirects.
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 (
For details, see Vanity Domains.
All redirect logic should include the
php_sapi_name() != "cli" conditional statement to see if WordPress or Drupal is running via the command line. Drush and WP-CLI are used by the platform for operations like cache clearing and search and replace, so it is important to only redirect web requests, otherwise the redirect will kill the PHP process before Drush or WP-CLI is executed, resulting in a silent failure:
[notice] Command: site.env -- 'drush <command>' [Exit: 1] [error]
Errors referencing too many redirects may be a result of using the
$_SERVER['HTTP_X_FORWARDED_PROTO'] variable within redirect logic located in your site's
Resolve this error by replacing the offending redirect logic with the recommended code samples in the above section and for your specific use case.
Modules and plugins that support managing redirects in the Site Admin interface can produce redirect errors when repeating or conflicting with redirects managed via PHP in your site's configuration file. Some examples include:
WordPress plugins: Redirection, Quick Page/Post Redirect, Safe Redirect Manager, Simple 301 Redirects
Drupal modules: Language (when using URL detection), Securepages, Redirect
When troubleshooting a redirect loop, you may want to deactivate any module or plugin that may be providing its own redirect logic.
If your domain's DNS configuration relies on an existing MX or TXT record that intentionally disallows CNAME records, you'll need to use
AAAA records to configure DNS for subdomains (e.g.,
www.example.com) instead of CNAMEs.
live-example.pantheonsite.io in the following URLs with the target environment's platform domain.
Identify the required
A record value by querying the target environment's platform domain using a free online tool, such as https://www.whatsmydns.net/#A/live-example.pantheonsite.io.
Do the same for the required
AAAA values. For example, https://www.whatsmydns.net/#AAAA/live-example.pantheonsite.io.
Log in to your DNS host and create two AAAA records and one A record for the desired subdomain (e.g.,
www) using the values returned in the steps above.
You can modify your local
hosts file to validate domain-specific settings before DNS is in place.
Note that modifying the
hosts file usually requires administrative privileges from the OS.
The location of the
hosts file varies depending on your operating system:
Add lines to your operating system's
hosts file in the following format:
203.0.113.10 example.com 203.0.113.20 www.example.com
In the example above, replace the IP addresses with those provided by Pantheon, and the domains with your own.