Railway Custom-Domain Limits & Workarounds — Quick Guide

README.md

Railway Custom-Domain Limits & Workarounds — Quick Guide

1. The Limitation

• Hobby plan → 2 custom-domain “slots” per service.
• Each hostname you add (www.example.com, admin.example.com, …) counts as one slot.

2. Simple DNS Pointing

Can you just CNAME a sub-domain to <app>.up.railway.app?	Yes, but…
Works for HTTP/HTTPS routing.	Railway won’t issue/renew TLS for that name because it’s unaware of it.
Good for quick tests.	You must supply SSL (e.g. Cloudflare) yourself.

3. One Service, Many Sub-domains (All on Railway)

Use a wildcard.

1. Delete existing hostnames in Settings ▸ Domains (free your slots).
2. Add a single wildcard: *.yourdomain.com
3. Create the DNS records Railway shows:
   • *.yourdomain.com CNAME <value>.up.railway.app
   • _acme-challenge.yourdomain.com CNAME authorize.railwaydns.net
4. (Optional) use the 2nd slot for the root domain yourdomain.com.

Result → every sub-domain (www, admin, api, …) reaches the same service over HTTPS, all within the free limit.

4. Mix & Match: Some Sub-domains on Railway, Others Elsewhere

1. Keep the wildcard setup above (costs 1 slot).

2. In your DNS zone, add explicit records that override the wildcard:

   four.yourdomain.com   A      <static-IP>
   docs.yourdomain.com   CNAME  docs.example.net