htmx

htmx is a lightweight, dependency-free JavaScript library that provides access to AJAX, CSS Transitions, WebSockets, and Server Sent Events directly through HTML attributes, allowing developers to build modern, dynamic user interfaces without writing complex client-side JavaScript. Created by Carson Gross and developed under the bigskysoftware organization, the library is the spiritual successor to intercooler.js and embodies the hypermedia architecture philosophy, treating the server as the source of truth and HTML as the application state transfer medium following HATEOAS principles. At approximately 16 kilobytes minified and gzipped, it extends standard HTML elements beyond anchors and forms so that any element can trigger HTTP requests, any event can trigger requests, and any HTTP verb can be used. Real-world case studies demonstrate code base size reductions of 67 percent when migrating from React to this approach. The library is currently at version 2.0.10 with version 4 in active beta development targeting a summer 2026 release. The official documentation includes comprehensive reference for all attributes, headers, events, and extensions, along with practical examples covering infinite scroll, inline validation, active search, progressive enhancement, and sorting. The project maintains an active essays section covering hypermedia systems architecture, the comparison with single page applications, and when to choose server-rendered HTML over JavaScript-heavy frameworks. The accompanying book Hypermedia Systems, co-authored by Carson Gross, Adam Stepinski, and Alex Petros, is freely available online. htmx was selected for the GitHub Accelerator program and is made in Bigfork, Montana, USA. Sponsors include commspace as Platinum sponsor and JetBrains.