---
title: useDecision hook for the React SDK
slug: feature-experimentation/docs/usedecision-react-prior-to-v4
docTags:
createdAt: 2026-08-05T20:39:51.000Z
---
**Minimum SDK version** – v2.5+
## `useDecision` hook
Retrieves the decision result for a flag key, optionally auto-updating that decision based on underlying user, datafile, or forced decision changes.
### Arguments
| Argument | Type | Description |
| ------------------------ | ------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| \`flagKey \`(required) | String | The key of the feature flag |
| \`options \`(optional) | Object | Includes the following:
- \`autoUpdate\` (boolean) - If true, this hook updates the flag decision in response to datafile or user changes. Default: \`false\`.
- \`timeout\` (number) - Client timeout as described in the \[\`OptimizelyProvider\`]\(https\://docs.developers.optimizely.com/feature-experimentation/docs/optimizelyprovider-react-prior-to-v4) documentation. Overrides any timeout set on the ancestor \`OptimizelyProvider\`.
- \`decideOptions\` (\`OptimizelyDecideOption\`) - Array of \`OptimizelyDecideOption\` enums. See \[OptimizelyDecideOption]\(#optimizelydecideoption). |
| \`overrides \`(optional) | Object | Includes the following:
- \`overrideUserId\` (string) - Override the userId to be used to obtain the decision result for this hook.
- \`overrideAttributes\` (optimizely.UserAttributes) – Override the user attributes to be used to obtain the decision result for this hook. |
### Returns
Returns an array with the following:
| Key | Type | Description |
| --------------- | --------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| \`decision\` | \[OptimizelyDecision]\(https\://docs.developers.optimizely.com/feature-experimentation/docs/optimizelydecision-react-prior-to-v4) | Decision result for the flag key. |
| \`clientReady\` | Boolean | Indicates whether the \`ReactSDKClient\` instance is ready. |
| \`didTimeout\` | Boolean | Indicates whether the \`ReactSDKClient\` instance became ready within the allowed timeout range. \`clientReady\` can be \`true\` even if \`didTimeout\` is also \`true\`. This indicates that the client became ready after the timeout period. |
### Example `useDecision`
```javascript
import { useEffect } from 'react';
import { useDecision } from '@optimizely/react-sdk';
function LoginComponent() {
const [decision, clientReady] = useDecision(
'flag1',
{ autoUpdate: true },
{
/* (Optional) User overrides */
}
);
useEffect(() => {
document.title = decision.enabled ? 'New Feature flag' : 'Old Feature flag';
}, [decision]);
return (
Click to login
);
}
```
## `OptimizelyDecideOption`
The following table lists the `OptimizelyDecideOption` enum with an explanation what happens if you set them. In addition to setting these options individually for a decide method, you can also set them as global defaults when you instantiate the Optimizely client. See [Initialize the React SDK](docId\:DNHADl7EzUwjramceiCdz).
| `OptimizelyDecideOption` enum | If set |
| ---------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `OptimizelyDecideOption.DISABLE_DECISION_EVENT` | Prevents the SDK from dispatching an [impression](../../end-user-docs/measure-and-analyze-results/what-are-impressions-and-decisions-in-feature-experimentation.mdx) event when serving a variation. This disables decision tracking on the [Optimizely Experiment Results page](../../end-user-docs/measure-and-analyze-results/optimizely-experiment-results-page.mdx). The [decision notification listener](../../developer-docs/configure/notification-listeners/decision-notification-listener.mdx) is still called, with `decisionEventDispatched` set to `false`. |
| `OptimizelyDecideOption.ENABLED_FLAGS_ONLY` | Returns decisions only for flags that are currently enabled. Used with the decide all method and decide for keys method.
When this option is not set, the SDK returns all decisions regardless of whether the flag is enabled. |
| `OptimizelyDecideOption.IGNORE_USER_PROFILE_SERVICE` | Bypasses the user profile service (both lookup and save) for the decision.
When this option is not set, user profile service overrides audience targeting, traffic allocation, and experiment mutual exclusion groups. |
| `OptimizelyDecideOption.INCLUDE_REASONS` | Adds log messages to the reasons field of the decision. Critical errors are always returned, even if this option is not set. |
| `OptimizelyDecideOption.EXCLUDE_VARIABLES` | Excludes flag variable values from the decision result. Use this option to minimize the returned decision by skipping large JSON variables. |
| `OptimizelyDecideOption.IGNORE_CMAB_CACHE` | Bypasses the CMAB cache and fetches a fresh decision from the CMAB service. Use when you need real-time decisions that reflect the latest context. |
| `OptimizelyDecideOption.INVALIDATE_USER_CMAB_CACHE` | Removes the cached CMAB decision for this user and experiment before making the decision. Use when user context has changed significantly and you want to ensure a fresh decision. |
| `OptimizelyDecideOption.RESET_CMAB_CACHE` | Clears all entries from the CMAB cache before making the decision. Use sparingly for testing or cache corruption scenarios. |
The following example shows how you can set options individually on the `useDecision` hook, or as global defaults when you instantiate the Optimizely client. See [Initialize React SDK](docId\:DNHADl7EzUwjramceiCdz).
```javascript
import { useEffect } from 'react';
import {
createInstance,
OptimizelyProvider,
useDecision,
OptimizelyDecideOption,
} from '@optimizely/react-sdk';
// Instantiate an Optimizely client
const optimizelyClient = createInstance({
sdkKey: 'Your_SDK_Key', // Replace with your SDK key
defaultDecideOptions: [OptimizelyDecideOption.DISABLE_DECISION_EVENT],
});
function LoginComponent() {
const [decision, clientReady] = useDecision(
'flag1',
{
autoUpdate: true,
decideOptions: [
OptimizelyDecideOption.ENABLED_FLAGS_ONLY,
OptimizelyDecideOption.IGNORE_USER_PROFILE_SERVICE,
],
},
{
/* (Optional) User overrides */
}
);
useEffect(() => {
document.title = decision.enabled ? 'New Feature flag' : 'Old Feature flag';
}, [decision]);
return (
Click to login
);
}
function App() {
return (
);
}
```