---
title: Track event method for the Flutter SDK
slug: feature-experimentation/docs/track-event-flutter
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

1.0.1 or higher. See [Minimum version support](docId:2shbZfPCkPAZ0mlZpL1TU).

## Description

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

You call the Track Event method on a user. For information about the user object, see [ OptimizelyUserContext for the Flutter SDK](docId\:qkagdzXifMComMybuU4ls).

:::hint{type="warning"}
The attributes passed to `trackEvent` 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.

## Example

```dart
var attributes = <String, dynamic>{};
attributes["logged_in"] = true;
var user = await flutterSDK.createUserContext(userId: "user123", attributes: attributes);

//Map of event properties
Map<String, dynamic> properties = {
    "category": "shoes",
    "color": "red"
};

// Map of event tags
Map<String, dynamic> tags = {
  "revenue": 10000,
  "value": 100,
  "$opt_event_properties": properties
};

// trackEvent(eventKey (required), eventTags (optional)
await user!.trackEvent("my_purchase_event_key", tags:tags);
```

## 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 Flutter are available on GitHub.

- **Flutter Android**  – [Optimizely.java](https://github.com/optimizely/java-sdk/blob/master/core-api/src/main/java/com/optimizely/ab/Optimizely.java)
- **Flutter iOS** – [OptimizelyClient.swift](https://github.com/optimizely/swift-sdk/blob/master/Sources/Optimizely/OptimizelyClient.swift)