How to Read an External Local JSON File in JavaScript

Discover different methods to read an external local JSON file in JavaScript, including Fetch API and XMLHttpRequest, with step-by-step examples.
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How to Read an External Local JSON File in JavaScript

JavaScript is a powerful and flexible language widely used for web development. One frequently encountered task is reading data from an external local JSON file and using it in your applications. In this guide, we will discuss two common methods to achieve this: the Fetch API and XMLHttpRequest.

Using Fetch API

The Fetch API is a modern, promise-based approach to make HTTP requests in JavaScript. It's straightforward to use and has more features compared to older techniques.

Here’s a simple example of how to read a local JSON file using Fetch API:

[[See Video to Reveal this Text or Code Snippet]]

Using XMLHttpRequest

Before the Fetch API, XMLHttpRequest was the go-to method for making HTTP requests in JavaScript. While it’s older and slightly more complex, it’s still widely used and supported.

Here is an example of reading a local JSON file using XMLHttpRequest:

[[See Video to Reveal this Text or Code Snippet]]

Advantages of Each Method

Fetch API:

Promise-based, making the code more readable.

More powerful with additional features like abort() to cancel a fetch request.

Better error handling.

XMLHttpRequest:

Broad browser support, especially with legacy systems.

Provides low-level control over the request and response.

Conclusion

In this post, we have explored two methods to read an external local JSON file in JavaScript: the modern Fetch API and the traditional XMLHttpRequest. Both methods have their pros and cons, and the choice between them may depend on your specific needs and the environments you are targeting. Whether you are looking for simplicity and readability or wide browser compatibility, JavaScript provides flexible options to manage JSON data easily and efficiently.