Flutter’s New Web Dev Proxy: A Cleaner Way to Handle APIs (No More CORS Headaches)

If you’ve ever built a Flutter web app, you’ve probably run into one annoying issue: CORS errors during development.

Traditionally, fixing this meant:

• tweaking backend headers
• setting up a reverse proxy (like Nginx)
• or using messy workarounds

But Flutter recently introduced something that simplifies all of this:

A built-in web development proxy

And honestly, it’s one of those small features that makes a huge difference in day-to-day workflow.

What Is Flutter’s Web Dev Proxy?

Flutter now allows you to define a local proxy using a simple config file:

web_dev_config.yaml

This lets your Flutter web app forward API requests to your backend automatically, without worrying about CORS.

My Setup

Here’s the exact configuration I’m using:

server:
  host: "0.0.0.0"
  port: 8000

  proxy:
    - target: "<target_url>"
      prefix: "/api/"

    - target: "<target_url>"
      prefix: "/files/"

How It Works

This setup means:

• Requests to /api/... → forwarded to your backend
• Requests to /files/... → also forwarded to your backend

So in your Flutter code, you can simply write:

http.get(Uri.parse('/api/users'));

And Flutter will internally send it to:

<target_url>/api/users

No CORS issues. No extra setup.

Why This Is a Big Deal

1. No More CORS Configuration

You don’t need to:

• enable CORS on your backend
• install middleware
• debug browser errors

3. No External Proxy Needed

Previously, many developers used:

• Nginx
• webpack dev server proxies
• custom scripts

Now Flutter handles it natively.

Optional: HTTPS Support

If you want to test secure environments locally, you can enable HTTPS:

https:
  cert-path: "/path/to/cert.pem"
  cert-key-path: "/path/to/key.pem"

If you’re building Flutter web apps, this is definitely worth adding to your workflow.

Just create a web_dev_config.yaml, define your proxy rules, and run your app.