> ## Documentation Index
> Fetch the complete documentation index at: https://docsuncv2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# sethiddenproperty

Modifies the value of a hidden property on a Roblox instance.

```luau theme={null}
sethiddenproperty(instance: Instance, property: string, value: any): boolean
```

## Parameters

| Parameter  | Type       | Description               |
| ---------- | ---------- | ------------------------- |
| `instance` | `Instance` | The target Instance.      |
| `property` | `string`   | The hidden property name. |
| `value`    | `any`      | The value to set.         |

## Returns

`boolean` - `true` if set successfully, `false` otherwise.

## Example

<CodeGroup>
  ```luau Example 1 theme={null}
  local success = sethiddenproperty(fireInstance, "size_xml", 10)
  assert(success)
  ```

  ```luau Example 2 theme={null}
  sethiddenproperty(workspace.Terrain, "PhysicsGrid", rawBytesData)
  ```
</CodeGroup>

<Tip>
  Modifying hidden properties allows changing physics states and internal structures.
</Tip>