# useTask$()

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Use [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) to execute a function before the initial render and whenever the tracking values change. The function executes before rendering, but it can't delay rendering, so if [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) is asynchronous, the rendering will happen before the [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) is fully executed.

## Tracking store changes

The [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) hook receives a `track()` function used for setting up subscriptions that will automatically rerun the [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) hook. The set of `track()` properties resets on each [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) execution, therefore it is important to always use `track()` to set up subscriptions anew. Because of this it is possible for the [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) to subscribe to different properties over time.

## Cleanup

The [`useTask$()`](https://qwik.builder.io/docs/components/lifecycle/#usetask) hook can return a cleanup callback. This is useful for cleaning up any resources before new execution.
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###### tags: `Lifecycle Hooks`