Introducing the IndexedDB API

Get a brief introduction to the IndexedDB API along with its use cases and characteristics.

What is the IndexedDB API?

IndexedDB is a powerful, low-level API for client-side storage of large amounts of structured data. It is a NoSQL database, which means that it doesn’t use tables and rows like traditional SQL databases. Instead, it uses an object-oriented model to store and retrieve data. This makes it perfect for applications that require fast and flexible storage on the client side, such as web applications.

The IndexedDB API is a key-value database that runs in the browser. Unlike other storage mechanisms such as the sessionStorage or localStorage objects, the IndexedDB API is accessed asynchronously, which makes it suitable for service workers with asynchronous nature.

Uses of the IndexedDB API

The IndexedDB API allows us to store structured data such as JSON, XML, or JavaScript objects, arrays, and significant amounts of unstructured data, including files/blobs.

The IndexedDB API can store formatted response data, transformed response data, and pieces of response data. Unlike app shell assets, which should be stored in the cache, IndexedDB is designed to store structured and unstructured data.


Here are some advantages of the IndexedDB API.

Offline accessibility

One of the main advantages of the IndexedDB API is its offline capability. Web applications that use IndexedDB can continue to work even if the user’s internet connection is lost. This means that users can continue to use the application, and their data will be saved and synced when the connection is restored. This makes IndexedDB an excellent choice for web applications that need to work both online and offline.


Another advantage of IndexedDB is its scalability. Unlike other client-side storage solutions like the localStorage, IndexedDB can handle large amounts of data, making it ideal for applications that store large amounts of structured data. It’s also fast and efficient, essential for web applications requiring quick response times.


We can access the application’s IndexedDB from both the page JavaScript and the service worker. It’s important to note that the sessionStorage or localStorage objects cannot be used in a service worker as they are accessed synchronously, making IndexedDB the preferred storage mechanism.

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