[Home](./index.md) > [puppeteer](./puppeteer.md) > [EventEmitter](./puppeteer.eventemitter.md) > [on](./puppeteer.eventemitter.on.md) ## EventEmitter.on() method Bind an event listener to fire when an event occurs. Signature: ```typescript on(event: EventType, handler: Handler): EventEmitter; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | event | EventType | the event type you'd like to listen to. Can be a string or symbol. | | handler | Handler | the function to be called when the event occurs. | Returns: [EventEmitter](./puppeteer.eventemitter.md) `this` to enable you to chain calls.