htmx 4.0 is under construction — migration guide

htmx:response:error

When an HTTP error status (4xx/5xx) is received

The htmx:response:error event fires when the server responds with an HTTP error status code (400 or higher).

When It Fires

After htmx:after:request and before the swap phase, when response.status >= 400.

This event does not fire for network errors or timeouts — use htmx:error for those.

Event Detail

  • ctx - The full request context, including:
    • ctx.response.status - The HTTP status code
    • ctx.response.headers - Response headers
    • ctx.text - The response body

Example

htmx.on('htmx:response:error', (evt) => {
  let status = evt.detail.ctx.response.status;
  console.error(`HTTP ${status} error`);
});

Migration from htmx 2

This event replaces htmx 2’s htmx:responseError. The event detail structure has changed — the response information is now available via evt.detail.ctx.response rather than directly on evt.detail.