If necessary, you can add a subdomain to your existing domain by creating an additional project in Onepage. This approach is particularly useful if you want to display different content on your main domain and your subdomain.
For example, your main domain can showcase your general services or products, while the subdomain is used for a special offer or campaign.
Please make sure your main domain is connected correctly. For more information, see our guide: How do I connect my domain and which method should I use?
Once your domain is successfully set up, you can connect your subdomain either internally via a new Onepage project or through an external service. Both options are explained below.
📌 Please note: These instructions apply only to customers who have already successfully connected their primary domain to Onepage.
Link the subdomain internally via a new Onepage project
Let's look at this method using an example: You already have a project with the domain mypage.com and would like to create an additional subdomain, such as offer.mypage.com.
Step 1: Create a new project
Go to the "Projects" section in Onepage and click "Create project".
Step 2: Open the domain settings
After creating the new project, go to Project settings → Domain settings and click "Connect Your Own Domain".
Step 3: Add your subdomain
Enter your desired subdomain along with your domain.
For example: offer.mypage.com
Step 4: Copy the CNAME record
A CNAME record will be created automatically. Copy it and confirm by clicking Okay, got it.
You'll need this entry in the next step.
Step 5: Open the DNS settings for the main domain
Switch back to your project with the main domain (mypage.com) and open Project settings → Domain settings again.
Click the three dots next to the domain and select "Edit DNS settings".
Step 6: Add the new CNAME record
Add a new entry to the DNS settings:
Type: CNAME
Name: offer (only the subdomain, without the domain)
Target: whitelabel.onepage.io
TTL: 300
📌 Please note: It may take 1-2 hours for the settings to be applied. During this time, the new subdomain may be offline.
Connect a subdomain to an external service
Let's look at this method using an example: You've already connected a project with the domain mypage.com to our service and want to connect the subdomain offer.mypage.com to an external service (e.g., a store, appointment booking, or tracking system).
📌 Please note: This method only works if your main domain is connected via Onepage's nameservers.
If you've connected your domain using A records or CNAME entries instead, you'll need to manage the DNS settings directly with your domain provider and create the necessary entry there.
Step 1: Open the DNS settings for the main domain
Open the Onepage project associated with your main domain (mypage.com). Navigate to Project settings → Domain settings.
Then click the three dots next to your main domain and select "Edit DNS settings".
Step 2: Add a CNAME record
Add a new DNS record with the following values:
Type: CNAME
Name: offer (only the subdomain, without the main domain)
Target: This value must be provided by the external service, you want to connect to.
TTL: 300 (or follow the instructions of the external service)
📌 Please note: It may take up to 1-2 hours for the changes to take effect. During this time, the subdomain may not yet be accessible.
If the subdomain points to an external service, Onepage cannot provide the SSL certificate. In this case, the SSL certificate must be created and managed by the respective external service.
Depending on the provider, a CAA record may also be required. To learn how to create a CAA record in Onepage, see our help article on the topic.
Frequently Asked Questions (FAQ)
My subdomain is connected to an external service. Why isn't an SSL certificate being generated?
My subdomain is connected to an external service. Why isn't an SSL certificate being generated?
If your subdomain is connected to an external service and an SSL certificate is not being generated, this is often due to a missing CAA record.
Please contact the provider of the external service and ask for the required CAA record. The CAA record specifies which certificate authorities or service providers are authorized to issue SSL certificates for your subdomain.
Once you have received the necessary information, add the CAA record to the DNS settings in Onepage or with your domain hosting provider. The external service should then be able to generate the SSL certificate for your subdomain.
Is it possible to link multiple subdomains to a single project?
Is it possible to link multiple subdomains to a single project?
Yes, multiple subdomains can be linked within a single project.
However, this feature is intended solely for setting up redirects to the same project. The number of available subdomains may be limited depending on your subscription plan. You can find a detailed overview in our pricing plan.
If you want your main domain and the subdomain to display different content, you’ll need a separate Onepage project for the subdomain. This is the only way to manage both addresses independently and populate them with different content.
💡Do you have any feedback concerning this article? Please let us know through our live chat or at support@onepage.io, so we may keep it up to date. Thank you! 🙂