---
title: Track event for the React SDK
slug: feature-experimentation/docs/usetrackevent-react-prior-to-v4
docTags: 
createdAt: 2026-08-05T20:40:01.000Z
---

Tracks a conversion event for a user. In other words, tracks an action a user takes. Logs an error message if the specified event key does not match any existing events. See [How Optimizely Experimentation counts conversions](#).

## Version

SDK 3.2 and higher. See [Minimum version support](docId:2shbZfPCkPAZ0mlZpL1TU).

## Description

Use the `useTrackEvent` hook to track events across multiple flag rules for a user. You should make only one track call per conversion (user action), even if many rules measure the conversion.

To use this hook, call `useTrackEvent` within a component wrapped by OptimizelyProvider. See [OptimizelyProvider for the React SDK](docId\:qRvVn4ymy4t0bPqQGggsf).

:::hint{type="warning"}
The attributes passed to `useTrackEvent` are *only* used for [results segmentation](docId:_K6n7h_MZ8b0xn6yWPrrq) on the [Optimizely Experiment Results page](docId\:mrUblIuNVOZc1dvjWdsbw).
:::

## Parameters

- `eventKey` (required) – String – The key of the event to be tracked. This key must match the event key provided when the event was created [in the Optimizely app](docId\:Bf3o37J3IJTUuVR7GshGd) or [REST API](docId\:NxpGs0D4LibV6Jp26feiJ).
- `eventTags` (optional) – Map – A map of key-value pairs specifying the [reserved tag keys](docId\:TPYh_YgbEQNnWIXKthzhl) names and their corresponding values for this particular event occurrence. `eventTags` are contextual metadata about [conversion events](docId\:onBazDzYYz526tL9aQF0s). For example, revenue, load time, or total value. The following are available tag keys:
  - `revenue` – An integer value that is used to track the revenue metric for your experiments, aggregated across all conversion events. `revenue` is recorded in cents.
  - `value` – A floating point value that is used to track a custom value for your experiments. Use this to pass the value for numeric metrics.
  - `$opt_event_properties` –   A map of default and custom event properties and their values.

See [reserved event tags](docId\:TPYh_YgbEQNnWIXKthzhl).

## Returns

This method sends conversion data to Optimizely Feature Experimentation. It does not provide return values.

## Examples

### useTrackEvent hook

Enables tracking events within functional components. This hook offers the existing track event functionalities provided by the SDK.

```javascript
// Assuming there is an OptimizelyProvider wrapping this component
import { useTrackEvent } from "@optimizely/react-sdk";

function SignupButton() {
  const [track, clientReady, didTimeout] = useTrackEvent();

  const handleClick = () => {
    if (clientReady) {
      // Define event properties
      const properties = {
        "category": "shoes",
        "color": "red"
      };

      // Define tags including event properties
      const tags = {
        "revenue": 10000,
        "value": 100.00, 
        "$opt_event_properties": properties
      };

      // Track event with tags
      track("signup-clicked", tags);
    }
  };

  return <button onClick={handleClick}>Signup</button>;
}
```

### track

You can use the `track `method of react client directly.

```javascript
import { createInstance } from "@optimizely/react-sdk";

const client = createInstance({
  sdkKey: SDK_KEY,
});

client.track("test_event", undefined, {
	custom_attr: "value"
})
```

### trackEvent

You can also use the `trackEvent` method of a user context.

```javascript
import { createInstance } from "@optimizely/react-sdk";

const client = createInstance({
  sdkKey: SDK_KEY,
});

const userContext = client.getUserContext()

userContext.trackEvent("test_event")
```

## Side effects

Additional Feature Experimentation functionality may be triggered by using this method.

### Conversions

Calling this method records a conversion and attributes it to the variations that the user has seen. See [How Optimizely Experimentation counts conversions](docId\:onBazDzYYz526tL9aQF0s).

You can create [metrics](docId\:e2qGf29S6pO8SW90_IVuH) on this conversion event and add metrics to experiments even after the conversion is tracked. See [Events: Tracking clicks, pageviews, and other visitor actions](docId\:puGm9z4XkEG5PDkyaNmlA).

:::hint{type="danger"}
This method does not track events if the event key is invalid.

Changing the traffic allocation of running experiments affects how conversions are recorded and variations attributed to users. See [Why you should not change a running experiment](docId\:IsU8ejnD3mrkAia2mtIOA).
:::

### Notification listeners

Accessing this method triggers a call to the [track notification listener](docId\:PaUUiwg7zYOguMb_HrFGN).

:::hint{type="danger"}
This method does not call the `TRACK` notification listener if the event key is invalid.
:::

## Source files

The language and platform source files containing the implementation for React are available on [GitHub](https://github.com/optimizely/react-sdk/blob/master/src/index.ts).