Redirect www traffic to a naked domain in Rails

Naked domains, or root domains, are hosts without the leading www. This blog is a perfect example, They are more succinct, direct, and easier to read.

If you set this up it’s also important to redirect www to the naked domain. Without the redirect, Rails might set up separate cookies for the two domains. So someone signed in on might not be on

A single Rails route

In Rails, you can redirect the www traffic with a single redirect in your routes configuration.

match "(*any)",
  to: redirect(subdomain: ""),
  via: :all,
  constraints: { subdomain: "www" }

Broken down:

  • match "(*any)" - matches any path to the site
  • to: redirect(subdomain: "") - removes the subdomain, in this case www
  • via: :all - matches all HTTP verbs (GET, POST, PUT, etc.)
  • constraints: { subdomain: "www" } - only match requests that start with www

It’s important to note that this must be the first line in the file. At a high level, Rails goes down the list to find a match. If something matches the request gets routed. Keeping this at the top ensures it happens before anything else.

Naked domains on Heroku

Before you convert your site to a naked domain make sure your domain registrar and DNS provider works with ALIAS or ANAME DNS records.

…Since Heroku uses dynamic IP addresses, it’s necessary to use a CNAME-like record (often referred to as ALIAS or ANAME records) so that you can point your root domain to another domain… - Heroku docs

Their list of approved DNS providers is limited. Hover, for example, doesn’t support these types of records. I ended up migrating to namecheap.