What counts as a subdomain

A subdomain is a prefix before your main domain, such as:

• www.example.com
• app.example.com
• shop.example.com
• blog.example.com
• help.example.com

Subdomains can behave like separate websites, even when they belong to the same business.

Use one site or multiple sites

Use one UserTrail site when the subdomains are part of the same visitor journey and should be reported together.

Use separate UserTrail sites when:

• different teams manage the subdomains
• reports should stay separate
• privacy settings are different
• the subdomains serve different products or clients
• one subdomain is an app and another is marketing

For example, you may track www.example.com and blog.example.com together, but keep app.example.com separate if it contains logged-in user data.

Install the snippet on each subdomain

To track a subdomain, install the UserTrail snippet on that subdomain. Adding a domain in UserTrail does not automatically install the script.

If you use the same site across multiple subdomains, install the same site snippet on each subdomain you want included in that site's reports.

Check privacy before tracking app subdomains

Application subdomains often contain private account data. Before tracking them:

• mask personal information
• exclude sensitive pages
• avoid recording payment or password fields
• confirm consent requirements
• test recordings before enabling broad traffic

If the app contains sensitive customer information, consider tracking only selected pages or not tracking the app subdomain at all.

Verify subdomain tracking

After installing the snippet:

1. Visit the subdomain.
2. Interact with a tracked page.
3. Open UserTrail Sessions.
4. Confirm the session path and host look correct.
5. Check Heatmaps for the tracked page.

Troubleshooting

If a subdomain is not recording:

• confirm the snippet is installed on that subdomain
• check tag manager triggers
• check Content Security Policy settings
• clear site and CDN cache
• test without browser extensions
• confirm consent allows the tracker to load