Js Fetch Api — Free Javascript Tutorial

TL;DR: Learn Js Fetch Api in Javascript with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.

Js Fetch Api in Javascript

The Fetch API is the modern way to make HTTP requests in JavaScript. It returns Promises, works with async/await, and replaces the older XMLHttpRequest. Used to load data from APIs, send form data, and interact with backends.

HTTP methods: GET (retrieve data), POST (create), PUT/PATCH (update), DELETE (remove). REST APIs follow these conventions. Most public APIs return JSON data.

Error handling: fetch() only rejects on network failure (no internet). For HTTP errors (404, 500), the promise RESOLVES but response.ok is false. Always check both: network catch AND response.ok.

Headers and request options: set Content-Type for POST requests, Authorization for authenticated APIs, and body for request data. JSON.stringify() converts JavaScript objects to JSON for sending.

// GET request:
const res = await fetch('https://api.example.com/data');
if (!res.ok) throw new Error(\

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