---title: Utilsdescription: This doc describes `jotai/utils` bundle.nav: 2.02---
This is an overview of the atom creators/hooks utilities that can be found under `jotai/utils`. Each utility is listed below with a link to their description/API.
## Overview
1. [atomWithStorage](../utils/atom-with-storage.mdx)
The `atomWithStorage` function creates an atom with a value persisted in `localStorage` or `sessionStorage` for React or `AsyncStorage` for React Native.2. [atomWithObservable](../utils/atom-with-observable.mdx)
The `atomWithObservable` function creates an atom from an RxJS (or similar) `subject` or `observable`. Its value will be last value emitted from the stream.3. [useUpdateAtom](../utils/use-update-atom.mdx)
Use `useUpdateAtom` and write-only atoms to avoid re-render.4. [useAtomValue](../utils/use-atom-value.mdx)
Returns the value of the given atom.5. [atomWithReset](../utils/atom-with-reset.mdx)
Creates an atom that could be reset to its `initialValue` with `useResetAtom` hook.6. [useResetAtom](../utils/use-reset-atom.mdx)
Resets a Resettable atom to its initial value.7. [RESET](../utils/reset.mdx)
Special value that is accepted by Resettable atoms created with `atomWithReset`, `atomWithDefault` or writable atom created with atom if it accepts `RESET` symbol.8. [useReducerAtom](../utils/use-reducer-atom.mdx)
Use this hook to update an atom value with a reducer function.9. [atomWithReducer](../utils/atom-with-reducer.mdx)
This is a function to create an atom with an embeded reducer function to update the value.10. [atomWithDefault](../utils/atom-with-default.mdx)
This is a function to create an overwritable primitive atom. Its default value can be specified with a read function instead of a static initial value.11. [atomWithHash](../utils/atom-with-hash.mdx)
This creates a new atom that is connected with URL hash.12. [atomFamily](../utils/atom-family.mdx)
This will create a function that takes param and returns an atom.13. [selectAtom](../utils/select-atom.mdx)
This function creates a derived atom whose value is a function of the original atom's value, determined by `selector`.14. [useAtomCallback](../utils/use-atom-callback.mdx)
This hook allows one to interact with atoms imperatively.15. [freezeAtom](../utils/freeze-atom.mdx)
The `freezeAtom` takes an existing atom and returns a new derived atom. The value with the new derived atom will be frozen (i.e. not mutable).16. [freezeAtomCreator](../utils/freeze-atom-creator.mdx)
Instead of creating a frozen atom from an existing atom, `freezeAtomCreator` takes an atom creator function and returns a new function.17. [splitAtom](../utils/split-atom.mdx)
The `splitAtom` utility is useful for when you want to get an atom for each element in a list.18. [waitForAll](../utils/wait-for-all.mdx)
The `waitForAll` utility is a concurrency helper, which allows us to evaluate multiple async atoms.19. [useHydrateAtoms](../utils/use-hydrate-atoms.mdx)
The primary use case for `useHydrateAtoms` are SSR apps like Next.js, where an initial value is e.g. fetched on the server, which can be passed to a component by props.