Drupal BigPipe Experiments with HTMX

Source: Drupal BigPipe Now Uses HTMX by Théodore Biadala (July 17, 2025)

Théodore Biadala has begun testing an HTMX-based frontend implementation inside Drupal’s BigPipe module. BigPipe, introduced in 2016, improves perceived performance by streaming cached content immediately and filling placeholders as they’re ready. Until now, it relied on simulated Ajax requests and Drupal’s Ajax framework, which requires ~40.7KB of compressed JavaScript. The new HTMX approach reduces that to ~21.2KB.

Biadala frames this as part of a longer-term effort to replace Drupal’s aging Ajax framework with HTMX and move closer to HATEOAS principles by keeping state in the DOM. He notes that BigPipe is a particularly difficult use case for HTMX integration—no Ajax requests, no HTMX events, and work happens before DOMContentLoaded. Still, it provides a useful test case for evaluating HTMX inside Drupal core. Developers interested in contributing can follow the related core issue or join the #htmx channel.