> ## Documentation Index
> Fetch the complete documentation index at: https://docs.domshot.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom User Agent

> Customize the user agent string

## Custom User Agent

Set a custom user agent to test how pages render for different browsers and devices.

<Tip>
  DomShot's default user agent is already optimized to bypass most bot detection systems, including Cloudflare. Only use a custom user agent when you need specific browser or device emulation.
</Tip>

## Basic usage

<CodeGroup dropdown>
  ```bash bash theme={null}
  curl "https://api.domshot.com/shot?key=YOUR_API_KEY&url=https://example.com&customUserAgent=%7B%22userAgent%22%3A%22Mozilla%2F5.0%20(iPhone%3B%20CPU%20iPhone%20OS%2014_0%20like%20Mac%20OS%20X)%22%7D" \
    --output screenshot.png
  ```

  ```typescript typescript theme={null}
  const userAgent = {
    userAgent: 'Mozilla/5.0 (iPhone; CPU iPhone OS 14_0 like Mac OS X)'
  };

  const params = new URLSearchParams({
    key: 'YOUR_API_KEY',
    url: 'https://example.com',
    customUserAgent: JSON.stringify(userAgent)
  });

  await fetch(`https://api.domshot.com/shot?${params}`)
    .then(res => res.blob())
    .then(blob => fs.writeFile('screenshot.png', blob));
  ```

  ```php php theme={null}
  $userAgent = [
    'userAgent' => 'Mozilla/5.0 (iPhone; CPU iPhone OS 14_0 like Mac OS X)'
  ];

  $params = [
    'key' => 'YOUR_API_KEY',
    'url' => 'https://example.com',
    'customUserAgent' => json_encode($userAgent)
  ];

  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, 'https://api.domshot.com/shot?' . http_build_query($params));
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
  $result = curl_exec($ch);
  file_put_contents('screenshot.png', $result);
  curl_close($ch);
  ```

  ```go go theme={null}
  package main

  import (
      "encoding/json"
      "net/http"
      "net/url"
  )

  type UserAgent struct {
      UserAgent string `json:"userAgent"`
  }

  func main() {
      userAgent := UserAgent{
          UserAgent: "Mozilla/5.0 (iPhone; CPU iPhone OS 14_0 like Mac OS X)",
      }

      params := url.Values{}
      params.Set("key", "YOUR_API_KEY")
      params.Set("url", "https://example.com")

      userAgentJSON, _ := json.Marshal(userAgent)
      params.Set("customUserAgent", string(userAgentJSON))

      resp, _ := http.Get("https://api.domshot.com/shot?" + params.Encode())
      defer resp.Body.Close()

      // Save response to file
  }
  ```
</CodeGroup>

## User agent object format

```json theme={null}
{
  "userAgent": "Mozilla/5.0 ...",
  "platform": "iPhone",
  "userAgentMetadata": {
    "brands": [
      {"brand": "Chrome", "version": "120"}
    ],
    "platform": "iOS",
    "platformVersion": "14_0",
    "architecture": "",
    "model": "iPhone",
    "mobile": true
  }
}
```

### Fields

| Field               | Type   | Required | Description                                   |
| ------------------- | ------ | -------- | --------------------------------------------- |
| `userAgent`         | string | No       | Full user agent string                        |
| `platform`          | string | No       | Platform identifier (e.g., "Win32", "iPhone") |
| `userAgentMetadata` | object | No       | Client Hints user agent data                  |

## Common user agents

| Use case       | User agent                                                     |
| -------------- | -------------------------------------------------------------- |
| Chrome Windows | `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36` |
| Safari iPhone  | `Mozilla/5.0 (iPhone; CPU iPhone OS 14_0 like Mac OS X)`       |
| Googlebot      | `Mozilla/5.0 (compatible; Googlebot/2.1)`                      |

<Warning>
  Custom user agents may trigger bot detection systems. The default DomShot user agent is optimized to bypass most protections including Cloudflare.
</Warning>

## Parameters

| Parameter         | Type   | Description                         |
| ----------------- | ------ | ----------------------------------- |
| `customUserAgent` | string | JSON object with user agent details |

## See also

* [Custom Headers](/guides/advanced/headers) - Set custom HTTP headers
* [Custom Cookies](/guides/advanced/cookies) - Set custom cookies