Sub domain usage for application

Most Saas companies seem to host their application on a sub domain rather than on a different domain. For example, the sales / marketing site might be hosted at and the application is at whereas we use for our sales site and then for our application.

Is this purely a personal preference thing or is there an advantage to hosting on a subdomain?

We were thinking mainly from an SEO perspective, does using the sub domain help? I assume it will make a difference on things like Alexa as it will show more traffic (I know Alexa is flawed) but also if anyone is linking to the application then it will be to a subdomain of our sales site which might help?

Curious to know if there is any benefit to using the subdomain option.

Separating out the configuration of routes allows for many different products, some of which are even ran by different companies even, to be used in the totality of execution of the web presence.

We host the app from a subdomain at Honeybadger – it allows us to host the app separately from the web site (www is just a static site, so it can even be hosted at s3), and it allows us to segregate google analytics. You are getting the same results by hosting on different domains. :slight_smile:

1 Like

Most likely your app site is not being indexed, given it probably requires authentication, thus you probably don’t have to worry about SEO value. Other sites that are not your primary marketing site (for example your support knowledge base or things like that) may benefit from being on the same primary domain. There may even be an argument for putting it on a subdomain, however this does make integrating with external services more difficult (although it can be done).

If you are running an operationally important service, then there is actually at least one thing you should have on a separate domain: your status site. That way if something goes terribly wrong with your primary domain you can at least access your status site to report the issue to customers.

One thing that can be either a benefit or a drawback, depending on how you use it, is the fact that subdomains have easy access to cookies, whereas I am not sure that is the case across different domains. It can be an advantage for connecting visits across sites together, but it can be a disadvantage if important cookie data leaks from your application over to non-application sites. Example article that talks about it (there are more):


(For us at DNSimple we just use subdomains except when we want a unique marketable domain, like or other micro-sites, and for our status site.)

1 Like

At we use subdomains for different products or services. For example the main site is a wordpress site on a linux server but our web app for converting word to HTML is on a windows server at

It is also useful for things like support. etc

Some advantages:

  • If the app goes down, your main marketing website will still be up and you can inform about outage
  • Traffic to the marketing site doesn’t affect the performance of your app
  • It’s much easier to use different technologies for the marketing site and app
  • You can deploy to the website without affecting your app
  • Marketing team can be authorized to make changes without breaking your app security
1 Like