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Overview

Emits a value from the source Observable, then ignores subsequent source values for a duration determined by another Observable, then repeats this process.
throttle is similar to audit, but emits the first value from the silenced time window instead of the last value.

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Type Signature

interface ThrottleConfig {
  leading?: boolean;
  trailing?: boolean;
}

function throttle<T>(
  durationSelector: (value: T) => ObservableInput<any>,
  config?: ThrottleConfig
): MonoTypeOperatorFunction<T>

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Parameters

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durationSelector
(value: T) => ObservableInput<any>
required
A function that receives a value from the source Observable, for computing the silencing duration for each source value, returned as an ObservableInput.
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config
ThrottleConfig
Configuration object to define leading and trailing behavior.
  • leading: If true, emit the first value (default: true)
  • trailing: If true, emit the last value when duration completes (default: false)

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Returns

MonoTypeOperatorFunction<T> - A function that returns an Observable that performs the throttle operation.

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Usage Examples

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Basic Example

import { fromEvent, throttle, interval } from 'rxjs';

const clicks = fromEvent(document, 'click');
const result = clicks.pipe(throttle(() => interval(1000)));

result.subscribe(x => console.log(x));
// Emits first click, ignores subsequent clicks for 1 second

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With Config

import { fromEvent, throttle, interval } from 'rxjs';

const clicks = fromEvent(document, 'click');
const result = clicks.pipe(
  throttle(() => interval(1000), { leading: true, trailing: true })
);

result.subscribe(x => console.log(x));
// Emits first click AND last click in each 1-second window
  • throttleTime - Same behavior but with fixed duration
  • audit - Emits last value instead of first
  • auditTime - Like audit but with fixed duration
  • debounce - Waits for silence before emitting
  • sample - Samples when another Observable emits