The Fetch API in JavaScript

The Fetch API is the modern, built-in way to make network requests in JavaScript. It replaces older methods like XMLHttpRequest and works perfectly with Promises and async/await.

Fetch is ideal for loading data from servers, sending forms, uploading files, or communicating with REST APIs. It's supported in all modern browsers and is simple yet powerful.

We'll cover everything step by step: basic requests, different HTTP methods, headers, JSON handling, response processing, error handling, and even advanced features like aborting requests.

Basic GET Request – Fetching Data

The simplest use is a GET request to retrieve data. Fetch returns a Promise that resolves to a Response object.

Always check response.ok and handle non-2xx statuses properly.

Using async/await – Cleaner Syntax

async/await makes Promise code read like synchronous code – much easier to follow.

POST Request – Sending Data

Use method: "POST" and include a body. For JSON, set the Content-Type header.

PUT and DELETE Requests

Update (PUT/PATCH) or delete (DELETE) resources.

Headers and Custom Options

Headers control content type, authentication, caching, etc.

Handling Non-OK Responses

Fetch doesn't reject on HTTP errors (4xx/5xx) – check response.ok manually.

Aborting Requests with AbortController

Cancel long-running requests (e.g., user navigates away).

Quick Quiz