Custom Domains and Routes in Cloudflare Workers

Aug 25, 2023 · 5 mins

You are new to Cloudflare Workers. You just created your first Worker but not sure what to do next. This is for you.

So a Worker is like a mini-application with a small piece of code that you would like to run. But when? That is when the Triggers tab on your Worker’s dashboard comes in. There are so many options there but for the sake of this post, we will only talk about Custom Domains and Routes.

Triggers

By default, when creating a Worker, you will be assigned to a domain like this <worker-name>.<subdomain>.workers.dev. It will show up in the Routes list, meaning that any request sent to that domain should trigger your Worker (if you haven’t disabled it). I don’t know about you but I personally don’t like lengthy subdomain routes like that. So I chose one of the options below.

Use Custom Domains

Using the dashboard interface to add Custom Domains is super quick and easy. It’s a one-click operation for websites on Cloudflare or using Cloudflare DNS (which is the requirement here).

Warning

You should note that custom domains point all paths of a domain or subdomain to your Worker, so be wise to choose a domain that won’t conflict with your main website. For example, if you have your website at abc.dev, you should not add abc.dev to your Worker again, instead you can use <subdomain>.abc.dev.

Use Routes

If you’re not a fan of the note above, then you can consider using Routes instead.

Routes allow users to map a URL pattern to a Worker. When a request comes in to the Cloudflare network that matches the specified URL pattern, your Worker will execute on that route.

Routes can be a little bit trickier than Custom Domain. If you intend to use some routes without a subdomain like abc.dev/api/something then adding it by clicking on Add route in the dashboard is enough. But what if you want use something like api.abc.dev/something, then you will need to set up a DNS record with Cloudflare proxy (orange-clouded) for the website first. If the subdomain you intend to use here will not be used in anything else, simply point it to Cloudflare.

TypeNameIPv4 addressProxy status
Awww192.0.2.1Proxied

Then you can use the Add route button the dashboard.

Note

Route pattern matching considers the entire request URL, including the query parameter string. Since route patterns may not contain query parameters, the only way to have a route pattern match URLs with query parameters is to terminate it with a wildcard, *.

Final notes

After setting all these configurations on the dashboard, all will be saved to wrangler.toml file in the Worker project, make sure you don’t accidentally replace that configuration when deploying new code to the Worker.

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