# Broken Link Checker (/docs/experiments/broken-link-checker)



Fetch a webpage, extract `a[href]` links, and probe each URL's HTTP status from Cloudflare's edge.

## Features [#features]

* Extracts absolute and same-origin relative links from HTML
* Probes up to 25 links by default (max 50) with HEAD, falling back to GET
* Runs probes concurrently (5 at a time) with per-link timeouts
* Stateless; no bindings required

## API Reference [#api-reference]

### GET /check [#get-check]

<TypeTable
  type="{
  url: {
    description: &#x22;The target page URL (must be http or https)&#x22;,
    type: &#x22;string&#x22;,
    required: true,
  },
  limit: {
    description: &#x22;Max links to probe (default 25, max 50)&#x22;,
    type: &#x22;number&#x22;,
    required: false,
  },
}"
/>

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

```bash
curl "https://your-worker.workers.dev/check?url=https://www.cloudflare.com&limit=10"
```

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

**`url`** `string`

Final page URL after redirects

**`checked`** `number`

Number of links probed

**`broken`** `number`

Count of non-OK responses

**`links`** `array`

Per-link `{ href, statusCode, ok, error? }`

```json
{
  "url": "https://www.cloudflare.com/",
  "checked": 10,
  "broken": 1,
  "links": [
    { "href": "https://www.cloudflare.com/", "statusCode": 200, "ok": true },
    { "href": "https://www.cloudflare.com/missing", "statusCode": 404, "ok": false }
  ]
}
```

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

* `400` - Missing or invalid `url` (`INVALID_URL`)
* `400` - Response was not HTML (`NOT_HTML`)
* `502` - Page fetch failed (`FETCH_ERROR`)

## Use Cases [#use-cases]

* Find dead links before publishing content
* Spot-check navigation and footer URLs
* Complement link extraction tools with live status checks
* Build simple site QA workflows on Workers

## Limitations [#limitations]

* Does not execute JavaScript; only links present in raw HTML
* Caps probes (default 25) to stay under Worker time limits
* Some origins block HEAD or bots; status codes may reflect bot filtering

## 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/broken-link-checker)
  </Step>

  <Step>
    ### Deploy [#deploy]

    Follow the deployment wizard. No bindings or secrets required.
  </Step>

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

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

## Local Development [#local-development]

```bash
cd apps/experiments/broken-link-checker
npm install
npm run dev
```

```bash
curl "http://localhost:8787/check?url=https://www.cloudflare.com"
```

## 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/)** - Page fetch and link probes

## Next Steps [#next-steps]

<Cards>
  <Card title="Browser Links" href="/docs/experiments/browser-links">
    Extract links from JavaScript-rendered pages
  </Card>

  <Card title="Is It Down" href="/docs/experiments/is-it-down">
    Check if a single URL is reachable from the edge
  </Card>
</Cards>