bigskysoftware/htmx

htmx is a small JavaScript library that lets you build interactive web pages without writing JavaScript. Instead of creating a separate JavaScript frontend that communicates with a server via JSON, htmx lets you add special HTML attributes directly to your existing HTML elements to define behaviors like sending requests, loading content, and updating the page. The core insight is that standard HTML is already a hypertext system, links navigate to pages and forms submit data, but with unnecessary restrictions: only links and forms can trigger requests, only clicks and submits start them, only GET and POST methods are supported, and the entire page always has to be replaced. htmx removes all of those constraints. You can make any HTML element (a button, a div, a table row) send any HTTP request (GET, POST, PUT, DELETE) on any event (click, hover, keypress, form change), and tell the server's response to replace only a specific part of the page rather than the whole thing. In practice, this means your server can return small HTML snippets that htmx inserts or swaps into the right location, making pages feel dynamic and responsive without a full single-page application framework. It also supports WebSockets and Server-Sent Events for real-time features via extensions. You would use htmx when building server-rendered applications in Python, Ruby, Go, or any backend language where you want dynamic UI interactions without the complexity of React, Vue, or similar JavaScript frameworks. It is particularly popular for teams who prefer keeping logic on the server. The library is written in JavaScript, weighs about 14 kilobytes compressed, has zero dependencies, and can be added to any page with a single script tag from a CDN. It is MIT licensed.