---
title: Visitor
slug: web-experimentation/api/II3W-visitor
docTags: 
createdAt: 2026-08-05T20:56:13.000Z
---

The `visitor` object contains all the attributes that can be used for targeting and segmentation.

### Syntax

```javascript
visitor = window["optimizely"].get("visitor");
```

### Parameters

| Parameter and Type   | Child Attribute | Description                                                   |
| -------------------- | --------------- | ------------------------------------------------------------- |
| **visitor** *string* | N/A             | The argument indicating to get visitor information. Required. |

### Return value

| Parameter and type                          | Child attribute                                  | Description                                                                                                                                                                |
| ------------------------------------------- | ------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| *VisitorData*                               | N/A                                              | The object contains all the attributes that can be used for targeting and segmentation.                                                                                    |
| **browserId** *string*                      | Child attribute of type `VisitorData`.           | A unique identifier for the browser type.                                                                                                                                  |
| **browserVersion** *string*                 | Child attribute of type `VisitorData`.           | The version of the browser.                                                                                                                                                |
| **source\_type** *string*                   | Child attribute of type `VisitorData`.           | Optimizely Web Experimentation evaluates how a visitor came to the website based on the referrer value. Possible values are `direct`, `search`, and `referral`.            |
| **visitorId** *string*                      | Child attribute of type `VisitorData`.           | A unique ID that Web Experimentation uses to identify a visitor.                                                                                                           |
| **custom** *object\[CustomAttributeObject]* | Child attribute of type `VisitorData`.           | An object whose keys are custom attribute IDs and whose values are `CustomAttributeObjects`. Contains values for all custom attributes that have been set for the visitor. |
| **id** *string*                             | Child attribute of type `CustomAttributeObject`. | The ID of the custom attribute, as displayed in **Audiences > Attributes** in the Optimizely UI.                                                                           |
| **value** *string*                          | Child attribute of type `CustomAttributeObject`. | The value of the custom attribute as set for the current visitor.                                                                                                          |
| `*` `*`                                     | Child attribute of type `VisitorData`.           | This object can contain project- or environment-specific properties that are not predefined.                                                                               |

### Example call

```javascript
visitor = window["optimizely"].get("visitor");
```

### Example return value

```javascript
{
  "browserId": "gc",
  "browserVersion": "53.0.2785.143",
  "source_type": "referral",
  "visitorId": "oeu1476217818972r0.36434468013549726",
  "custom": {
    "7973492630": {
      "id": "7973492630",
      "value": "High Tech"
    },
    "7995780411": {
      "id": "7995780411",
      "value": "commercial 1"
    }
  }
}
```