htmx 2.x Compatibility

The htmx-2-compat extension provides a compatibility layer that allows htmx 2.x code to run on htmx 4 with minimal changes. This is useful for gradual migration of existing applications.

Installing

<script src="/path/to/htmx.js"></script>
<script src="/path/to/ext/hx-htmx-2-compat.js"></script>

Usage

Once loaded, the extension maps old htmx 2.x APIs and behaviors to their htmx 4 equivalents, including:

• Old event names (e.g., htmx:afterSwap → htmx:after:swap)
• Implicit attribute inheritance (without requiring :inherited modifier)
• The hx-ext attribute for activating extensions
• Other htmx 2.x behaviors that changed in htmx 4

See the Migration guide for a full list of changes between htmx 2.x and htmx 4.