[Home](./index.md) > [puppeteer](./puppeteer.md) > [EventEmitter](./puppeteer.eventemitter.md) ## EventEmitter class The EventEmitter class that many Puppeteer classes extend. Signature: ```typescript export declare class EventEmitter implements CommonEventEmitter ``` ## Remarks This allows you to listen to events that Puppeteer classes fire and act accordingly. Therefore you'll mostly use [on](./puppeteer.eventemitter.on.md) and [off](./puppeteer.eventemitter.off.md) to bind and unbind to event listeners. The constructor for this class is marked as internal. Third-party code should not call the constructor directly or create subclasses that extend the `EventEmitter` class. ## Methods | Method | Modifiers | Description | | --- | --- | --- | | [addListener(event, handler)](./puppeteer.eventemitter.addlistener.md) | | Add an event listener. | | [emit(event, eventData)](./puppeteer.eventemitter.emit.md) | | Emit an event and call any associated listeners. | | [listenerCount(event)](./puppeteer.eventemitter.listenercount.md) | | Gets the number of listeners for a given event. | | [off(event, handler)](./puppeteer.eventemitter.off.md) | | Remove an event listener from firing. | | [on(event, handler)](./puppeteer.eventemitter.on.md) | | Bind an event listener to fire when an event occurs. | | [once(event, handler)](./puppeteer.eventemitter.once.md) | | Like on but the listener will only be fired once and then it will be removed. | | [removeAllListeners(event)](./puppeteer.eventemitter.removealllisteners.md) | | Removes all listeners. If given an event argument, it will remove only listeners for that event. | | [removeListener(event, handler)](./puppeteer.eventemitter.removelistener.md) | | Remove an event listener. |