# Persistent Storage

Your app can store a user's settings in various ways. For each usecase, there's a best practice.

## Device Settings

Most likely, you'll want to store settings per-device.

For front-end, user-visible settings, use [Device Settings](https://apps.developer.homey.app/the-basics/devices/settings).

For back-end, persistent settings, use the Device Store. Refer to [Device.getStoreValue](https://apps-sdk-v3.developer.homey.app/Device.html#getStoreValue) and [Device.setStoreValue](https://apps-sdk-v3.developer.homey.app/Device.html#setStoreValue) for the documentation.

## App Settings

Most app-specific settings can be stored and retrieved through [ManagerSettings](https://apps-sdk-v3.developer.homey.app/ManagerSettings.html). This enabled your app to save and retrieve any value that is JSON-serializable. App Settings are saved across app restarts, and are only deleted when your app is uninstalled.

On Homey Pro, a custom App Settings can be created using HTML, CSS and JavaScript.

{% hint style="info" %}
It is generally discouraged to use custom HTML, because often app settings are better to be stored within a Device Store.
{% endhint %}

## App Userdata

For non-JSON serializable data, e.g. binary files, the `/userdata/` folder is writable on Homey Pro.

{% hint style="danger" %}
The `/userdata/` is publicly available on `http`s`://<homey>/app/your.app.id/userdata/`.

This allows for some nice usecases, but can also be a security risk! Be sure to keep your filenames unique so they cannot be guessed.

For example, when storing an image, don't name it `image1.jpg` but `a656d380-c887-4d8b-9ee5-f89de7b65d01.jpg` and keep the Image's name stored in the App Settings.
{% endhint %}