Note: In late 2021, we changed how custom domains work to be even more powerful. Please ensure you’re using the most recent version of custom domains (set up in your site settings).
Why use a custom domain?
We recommend that all customers set up a custom domain to avoid losing traffic from visitors who use ad-blockers. Along with bypassing ad-blockers, using a custom domain give you access to advanced script settings like EU isolation, IP and country blocking and included domains.
Will a custom domain affect my site?
Adding a custom domain will not affect your main website, as it's a subdomain only. That means, no downtime for your site, and nothing changes about how your website loads or functions. A custom domain is just an additional DNS entry, specifically for your analytics. For example, if your site is
site.com, a custom domain you might add would be
cat.site.com, which means nothing about your main site would be any different, as your custom domain isn't your main site URL.
How to add a custom domain
Sites, then click on your site. Under your embed code, click
Set up a custom domain. If it’s already enabled, you’ll see
Script settings instead of the setup button.
You’ll now have two options:
- Random: This randomly generates a subdomain for you, which is best to avoid ad-blockers. For example,
- Specific: You can type one in if you want to use a specific subdomain. AVOID subdomains like
fathomas these are easily guessed and blocked by ad-blockers.
Add your domain by clicking
Add domain. Now, log into your domain registrar and create the new DNS record (add the CNAME and the value to your DNS). We’ll email you once it’s working. Typically this happens in a few minutes, but sometimes DNS updates can take many hours (we don’t have control over this).
If your domain is stuck on
pending be aware that some domain registrars require a dot/period at the end of the CNAME value for it work properly. When in doubt, check your domain registrar's documentation or ask their support.
Once we confirm the DNS update is
Active, your embed script will change to a custom domain, like this:
Use this in the head section of your site or anywhere you are embedding our script.
Using the same custom domain on any of your sites
If you've created a custom domain in Fathom, and it's showing as active, you can use it on any site in your account. Make sure you change the Site ID to the correct one for each site.
Note: If you use the same custom domain across multiple domains, you run the risk of an ad-blocker blocking your custom domain across ALL your sites (which is why we don't always recommend doing this). You also lose the ability to be site-specific with IP and country blocking features.
If your custom domain is blocked
On the off-chance that ad-blockers add your new custom domain to a blocklist (it’s unlikely, but it can happen if your site is popular), all you need to do is add your domain again, which generates a new CNAME and VALUE and use that instead. You’ll instantly be back to bypassing ad-blockers and won’t lose any data in the process.
Adding a custom CNAME on domain registrars
Every domain registrar is different in terms of editing DNS records, but here are links to a few popular ones:
- Adding a CNAME in Godaddy
- Adding a CNAME in Cloudflare (turn off proxy, the little orange cloud)
- Adding a CNAME in Hover
- Adding a CNAME in NameCheap
If you still have questions or require help with anything, please reach out to us and we'll happily get things sorted out for you.