# Debug Overlay

F3 toggles the overlay, F4 cycles features.

```{raw} html
<a class="example-run-button" href="../demos/features_debug_overlay.html">▶ Run in browser</a>

```

**Tags:** `debug`

Exercises the engine `Debug` HUD: profiler timings, UI control bounds,
labels, and an event log. UI controls (buttons, panels, dropdown) drive
the feature mix at runtime.

## Source

```{literalinclude} ../../examples/features/debug/overlay.py
:language: python
:linenos:
```