# htmx User Guide htmx is a small, dependency-free JavaScript library that lets you access modern browser features — AJAX requests, CSS transitions, WebSockets, and Server-Sent Events — directly from HTML attributes, without writing JavaScript. Instead of returning JSON and rendering it on the client, your server returns HTML, and htmx swaps that HTML into the page. This is the **hypermedia** approach: HTML stays the engine of application state. This guide is for web developers who want to add dynamic, interactive behavior to their pages using htmx. It covers installation, every `hx-*` attribute, request triggering, content swapping, forms, browser history, and troubleshooting — all written from the htmx source at version `2.0.10`. > [!NOTE] > htmx works with **any** server-side technology that can return HTML — Django, Rails, Flask, Express, Go, PHP, ASP.NET, or a static file server. htmx does not care what generates the HTML; it only cares that the response *is* HTML. --- ## 1. Quick Start Add htmx to your page with a single ` ``` When the button is clicked, htmx: 1. Sends an HTTP `POST` request to `/clicked`. 2. Receives an HTML fragment in the response. 3. Replaces the entire `