JavaScript Fetch Guide
The Fetch API provides a modern, promise-based interface for HTTP requests. It is the standard way to make network requests in JavaScript. The guide walks through GET & POST, Headers & Auth. `fetch(url)` — GET request. `fetch(url, {method:"POST", headers:{"Content-Type":"application/json"}, body:JSON.stringify(data)})` — POST JSON. `fetch(url, {method:"POST", body:formData})` — upload files. Check response: `if(!response.ok) throw Error(response.status)`. Parse: `await response.json()`, `response.text()`, `response.blob()`. Custom headers: `new Headers({Authorization:"Bearer token"})`. `fetch(url, {headers})`. Response headers: `response.headers.get("Content-Type")`. Basic Auth: `Authorization:"Basic "+btoa(user+":"+pass)`. Abort: `const ctrl=new AbortController(); fetch(url,{signal:ctrl.signal}); ctrl.abort()`. The guide is organized into 2 sections that build on each other, each pairing a prose explanation with runnable code. Related guides: Arrays, Strings, Numbers, Math, Date. This is one of 145 JavaScript guides on JS Reference — see the full list on the guides page. Practice what you learn in the JavaScript playground, and look up any unfamiliar term in the JavaScript glossary.