# The htmx Guide

> htmx guide: what htmx is, why hypermedia-driven apps beat SPA complexity for most projects, and how htmx fits the AHA Stack.

Author: Flavio Copes | Published: 2026-07-14 | Canonical: https://flaviocopes.com/htmx/

htmx is a small JavaScript library that lets you build dynamic web apps without writing JavaScript.

The idea: any HTML element can make an HTTP request, and the server responds with HTML that gets swapped into the page. A button can POST a form. A div can load its content lazily. A search box can fetch results as you type.

You express all of this with HTML attributes:

```html
<button hx-post="/clicked" hx-swap="outerHTML">
  Click me
</button>
```

When clicked, this button sends a POST request to `/clicked` and replaces itself with the HTML the server returns.

That's the whole model. The server renders HTML, htmx swaps it in. No JSON APIs, no client-side state management, no build pipeline.

## Why htmx matters

For years the default answer to "I need interactivity" was a full SPA framework. That brings a lot of complexity: client-side routing, state synchronization, hydration, huge bundles.

htmx pushes back on that. Your server stays the source of truth. Your pages stay HTML. You get the smooth, no-reload feel of an SPA while keeping the simplicity of server-rendered pages.

My advice: if your app is mostly forms, lists, and pages, htmx will get you there faster than React, and the result is easier to maintain.

## htmx in the AHA Stack

htmx is the "H" in the **AHA Stack**: Astro, htmx, Alpine.

Astro renders pages on the server. htmx handles the client-server communication, swapping fragments of HTML. Alpine covers the purely client-side bits, like toggling a dropdown.

I wrote hub pages for the other two parts as well: [the Astro guide](https://flaviocopes.com/astro/) and [the Alpine.js guide](https://flaviocopes.com/alpine/).

## Practical htmx posts

A few hands-on posts solving specific htmx problems:

- [HTMX, perform something on page load](https://flaviocopes.com/htmx-perform-something-on-page-load/) using the `load` trigger
- [htmx, redirect after request](https://flaviocopes.com/htmx-redirect-after-request/) with the `HX-Redirect` response header
- [htmx, send files using htmx.ajax()](https://flaviocopes.com/htmx-send-files-using-htmxajax-call/) for programmatic uploads

## Go deeper

I wrote a free ebook on htmx: the [htmx Handbook](https://flaviocopes.com/ebooks/htmx-handbook/). It covers the core attributes, triggers, swapping strategies, and how to structure a hypermedia-driven app. Free download, PDF and EPUB.

If you want to see the full picture, the [AHA Stack Masterclass](https://flaviocopes.com/courses/aha-stack) is my course on building complete applications with Astro, htmx, and Alpine working together.

All posts on this topic are in the [htmx tag archive](https://flaviocopes.com/tags/htmx/).