8 Local Storage Best Practices

Local storage is a powerful tool for web developers, allowing them to store data on the user’s computer and access it later. It’s a great way to store user preferences, application state, and other data that needs to be persisted across page loads.

However, local storage can be tricky to use correctly. In this article, we’ll discuss 8 best practices for using local storage in your web applications. By following these best practices, you can ensure that your local storage implementation is secure, efficient, and easy to maintain.

1. Use localStorage for data that won’t expire

LocalStorage is a great way to store data that won’t expire, such as user preferences or settings. This ensures that the data will be available even if the user closes their browser window or refreshes the page.

On the other hand, localStorage should not be used for sensitive information like passwords or credit card numbers. For this type of data, you should use an encrypted database instead. Additionally, it’s important to remember that localStorage can only store strings, so any complex objects must first be converted into a string before being stored.

2. Don’t store sensitive information in local storage

Local storage is stored in the browser, which means it can be accessed by anyone with access to that computer. This makes it vulnerable to malicious attacks and data breaches.

Therefore, you should never store sensitive information such as passwords, credit card numbers, or other personal information in local storage. Instead, use a secure server-side database for storing this type of data. Additionally, make sure your website is using HTTPS encryption to protect any data sent between the user’s browser and your server.

3. Avoid frequent access to local storage

Local storage is a synchronous API, meaning that when you access it, the browser will block any other activity until the data has been retrieved. This can cause performance issues if your application is making frequent requests to local storage.

To avoid this issue, try to minimize the number of times you need to access local storage. If possible, store all the necessary data in one request and then use that data for multiple operations. Additionally, consider using an asynchronous API such as IndexedDB or WebSQL instead of local storage. These APIs are designed to be more efficient and won’t block other activities while they’re being accessed.

4. Use try/catch when accessing local storage

When accessing local storage, there is a chance that the data stored in it may not be valid or available. This could happen if the user has disabled local storage, or if the browser does not support it. In such cases, an error will be thrown and your code will fail.

Using try/catch when accessing local storage helps you handle these errors gracefully. You can catch the error and display a message to the user informing them of the issue, or take other appropriate action. This ensures that your application continues to work even if local storage is unavailable.

5. Test your code on different browsers and devices

Different browsers and devices have different levels of support for local storage. For example, some browsers may not support certain features or may have a limited amount of space available for storing data. Additionally, the way that data is stored can vary from browser to browser.

By testing your code on multiple browsers and devices, you can ensure that it works properly across all platforms. This will help you avoid any potential issues with compatibility or performance.

6. Use JSON.stringify() to convert objects into strings before storing them

When you store an object in local storage, it is stored as a string. This means that if you try to access the object directly from local storage, you won’t be able to do so. Instead, you’ll need to use JSON.parse() to convert the string back into an object before you can work with it.

Using JSON.stringify() ensures that your objects are properly converted into strings before they’re stored in local storage. This makes them easier to retrieve and manipulate later on.

7. Use JSON.parse() to convert stored strings back into JavaScript objects

When you store data in local storage, it is stored as a string. This means that if you want to access the data and use it in your application, you need to convert it back into an object or array. JSON.parse() allows you to do this quickly and easily. It takes a string of JSON-formatted data and converts it into a JavaScript object or array.

Using JSON.parse() also helps ensure that the data you are retrieving from local storage is valid and secure. By parsing the data before using it, you can make sure that any malicious code or invalid data is not being used in your application.

8. Consider using a library like Store.js or Lawnchair

These libraries provide a simple API for working with local storage, making it easier to store and retrieve data. They also offer features like automatic serialization/deserialization of objects, support for multiple types of storage (e.g., IndexedDB, WebSQL, etc.), and the ability to set expiration times on stored items. This makes them ideal for applications that need to persist data across sessions or even when offline.