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# FinalizationRegistry.prototype.unregister()

The `unregister()` method unregisters a target object from a
`FinalizationRegistry` instance.

## Syntax

```js
unregister(unregisterToken)
```

### Parameters

- `unregisterToken`
  - : The token used with the [`FinalizationRegistry.prototype.register`](./register.mdx) method when registering the target object. Multiple cells registered with the same `unregisterToken` will be unregistered together.

### Return value

A boolean value that is `true` if at least one cell was unregistered and `false` if no cell was unregistered.

### Exceptions

- [`TypeError`](../../../globals/TypeError/TypeError.mdx)
  - : Thrown when `unregisterToken` is not an object.

## Description

When a target object has been reclaimed, it is no longer registered in the registry.
There is no need to call `unregister` in your cleanup callback. Only call
`unregister` if you haven't received a cleanup callback and no longer need
to receive one.
