# Response Headers (/experiments/response-headers)



Fetch any URL and return its HTTP status and response headers as JSON.

## API Endpoint [#api-endpoint]

### GET /headers [#get-headers]

Uses `HEAD` first and falls back to `GET` when the origin does not support `HEAD`.

**`url`** `string` (required)

The target URL (must be http or https)

#### Example Request [#example-request]

```bash
curl "https://your-worker.workers.dev/headers?url=https://www.cloudflare.com"
```

#### Success Response [#success-response]

**`url`** `string`

Final URL after redirects

**`statusCode`** `number`

HTTP status code

**`statusText`** `string`

HTTP status text

**`method`** `string`

`HEAD` or `GET`

**`headers`** `object`

Response headers as key/value pairs

```json
{
  "url": "https://www.cloudflare.com/",
  "statusCode": 200,
  "statusText": "OK",
  "method": "HEAD",
  "headers": {
    "content-type": "text/html; charset=utf-8",
    "server": "cloudflare"
  }
}
```

#### Error Codes [#error-codes]

* `400` - Missing or invalid `url` (`INVALID_URL`)
* `502` - Fetch failed (`FETCH_ERROR`)

## Use Cases [#use-cases]

* Debug cache and security headers from the edge
* Compare response headers across origins
* Learn HEAD vs GET fallback patterns in Workers

## Deployment [#deployment]

<Steps>
  <Step>
    ### Click the deploy button [#click-the-deploy-button]

    [![Deploy to Cloudflare Workers](https://deploy.workers.cloudflare.com/button)](https://deploy.workers.cloudflare.com/?url=https://github.com/shrinathsnayak/cloudflare-experiments/tree/main/apps/experiments/response-headers)
  </Step>

  <Step>
    ### Test your deployment [#test-your-deployment]

    ```bash
    curl "https://your-worker.workers.dev/headers?url=https://www.cloudflare.com"
    ```
  </Step>
</Steps>

## Local Development [#local-development]

```bash
cd apps/experiments/response-headers
npm install
npm run dev
```

## Cloudflare Features Used [#cloudflare-features-used]

* **[Workers](https://developers.cloudflare.com/workers/)** - Edge compute runtime
* **[Fetch API](https://developers.cloudflare.com/workers/runtime-apis/fetch/)** - HTTP requests from the edge