# element.once()

> Like on(), for the next event only.

Source: https://docs.tryyoursize.com/reference/web/element-once/

*Method* · `@tryyoursize/sdk`

Like `on()`, for the next event only.

```ts
once<K extends keyof ElementEvents>(event: K, handler: (e: ElementEvents[K]) => void): void;
```

## Parameters

- **`event`** (`keyof ElementEvents`, required): The event name.
- **`handler`** (`(e: ElementEvents[K]) => void`, required): Called once with the event payload.

## Example

**JavaScript**

```js
guide.once("ready", () => performance.mark("tys-ready"));
```