Step 3. Add a custom domain

Use a custom tagging server URL, also called a custom domain, to set first-party cookies. This URL should use the same root domain as your website. For example, if your website is `example.com`, your tagging server URL can be `ss.example.com`.

There are three ways to set up a custom domain:

• Same origin – tagging server shares the exact domain and path with your site. Read more on how to set up a custom domain with the same origin. 
• Subdomain – tagging server runs on a subdomain of your root domain. In this article we will guide you through this setup.
• Default domain – no custom domain; uses the standard Stape-provided address.

Сhoose your container on Stape, scroll down to the Domains (Tagging Server URLs) section, and click +Add new.

Add Subdomain name - it can be any name that works for you, just be sure to avoid using phrases specific to advertising or tracking: ad, gtm, stgm, tracking, analytics, metrics, stape, gtag, etc.

A Content Delivery Network (CDN) distributes your website's assets across a global network of servers to reduce latency and improve load times for users in different locations. It is useful if your audience is geographically distributed or if you want to improve cookie tracking and data accuracy.

By default, the CDN is disabled, which means JavaScript files (like gtm.js, gtag.js, and analytics.js) are served directly from the server location where your sGTM container is hosted. Effectively, it bypasses both Stape Global CDN and Own CDN options and gives you a direct, unproxied connection between your site and the sGTM container.

To enable the CDN, click the Add CDN toggle and select one of the following options:

• Stape Global CDN - loads scripts from a server closest to your website visitor's location, which reduces latency and improves page load times for geographically distributed audiences. We will use the Stape Global CDN in our setup. This feature is free and available for all Stape sGTM containers.
• Own CDN (incompatible with the Automatically (via Entri) connection option) - helps route sGTM custom domain and proxy sGTM traffic through the DNS provider of your website. In this case, the IP addresses of your website and the custom domain of the sGTM will match, and server-side cookies will be considered as first-party. As a result, it gives the ability to increase cookie duration.

Next, in the How to connect section, there are two ways of connecting a custom domain to your container:

• Automatically (via Entri)

The easiest way to connect domains. Log in with your DNS provider details via Entri, and give us one-time permission to connect your domain. That's it, you can proceed directly to Step 5 to verify your domain; no manual configuration is required.

• Manually

With this option, you have to add DNS records manually to your hosting provider to connect your subdomain to Stape.

After you add a custom subdomain to your container, you will see DNS records that should be created to verify the custom domain. The DNS record depends on the server location and the CDN option you choose. In the next step, we show how to add DNS records.

By default, subdomain verification is performed with CNAME records, but you can verify your subdomain with A and AAAA records if you need to (usually in cases when you need to avoid adding duplicated records).

We will cover both options below with a step-by-step guide on how to create records using Cloudflare. But you can use any other provider.

Once you've entered the DNS records to your DNS provider, return to the Stape container page where you've been configuring the custom domain and click Verify.

Wait for Stape to finish verifying your custom domain (when the container status bar changes from Verifying to Ready). Usually, it takes 2-3 hours to verify the custom domain. For some DNS providers, verifying records might take up to 72 hours. We will email you once the custom domain is verified or any error is detected.

If you face any problems with domain verification, please follow our guide on troubleshooting a custom domain.

Go to your Google Tag Manager server container → Admin → Container Settings → change Tagging server URL to your subdomain.

Update the script

If you use a custom domain, updating the Web GTM script on your website is highly recommended. This tweak will load gtm.js from your domain. To do so, replace the default domain googletagmanager.com with the custom domain you set up in the previous step.

Alternatively, you can automate this process with the Custom Loader power-up. Instead of manually editing the GTM script, Custom Loader generates a ready-to-use code snippet that loads GTM and GA4 scripts directly from your custom domain. This saves your time, makes your tracking scripts more resilient to ad blockers, and assures all cookies are treated as first-party.

You’ll see your new custom domain in your sGTM container’s list of domains. If you’re on a paid subscription, you will also see the Tracking Score estimating the quality of your domain’s tracking setup.

Click on your domain to access its settings:

Click Score to get more information about the Tracking Score report. Tracking Score report gives you an overview of your tracking setup health. Be sure to click the View full report button to get the full information, or New scan to update the report. Learn more about what constitutes a full report in our guide.