> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ozu.studio/llms.txt
> Use this file to discover all available pages before exploring further.

# Playback Controls

> JKL shuttle, snap grid, in/out points, loop, and speed control for the Timeline editor.

The Timeline editor uses a classic **JKL** transport — the same three-key shuttle professional editors have used since the 90s. Learn it once and muscle memory takes over.

## JKL shuttle

The three keys that run everything:

| Key   | Action          |
| ----- | --------------- |
| **J** | Play in reverse |
| **K** | Pause           |
| **L** | Play forward    |

Hold **K while pressing L** to play forward at half-speed — useful for auditioning a cut frame-by-frame. The same trick works in reverse: hold **K + J** for half-speed reverse.

Tap **L** repeatedly to speed up forward playback; tap **J** to speed up reverse. Tap **K** at any time to stop.

<Tip>
  **Why JKL?** They sit under your right hand's index, middle, and ring fingers. You can shuttle without looking at the keyboard while your left hand is on the mouse. Every video editor — Premiere, Final Cut, Avid, DaVinci Resolve — uses the same shortcut.
</Tip>

## Scrubbing

Drag the **playhead** (the vertical line running through the tracks) along the timecode ruler to scrub. The Preview Monitor updates in real time.

Click anywhere on the timecode ruler to jump the playhead there. **Home** returns to the start; **End** jumps to the last clip.

## Snap grid

The snap grid aligns clips to consistent time divisions. When it's on, dragging a clip snaps its edge to the nearest grid line.

| Key                             | Action                                 |
| ------------------------------- | -------------------------------------- |
| **S**                           | Toggle snap grid on/off                |
| **Shift (held while dragging)** | Temporarily disable snap for that drag |

Snap is on by default. Turn it off for micro-adjustments, or hold **Shift** for a one-off override without changing the setting.

## In and out points

Every timeline has an **in point** and an **out point** — the range rendered when you export an MP4. By default they cover the whole timeline.

| Key   | Action                                         |
| ----- | ---------------------------------------------- |
| **I** | Set in point at the current playhead position  |
| **O** | Set out point at the current playhead position |

The in/out range highlights on the timecode ruler. Drag either marker to move it, or set both via the Inspector's numeric fields.

1. **Scrub to where you want the export to start.** Press **I**.

2. **Scrub to where you want the export to end.** Press **O**.

3. **Export.** The MP4 renders only the range between in and out.

This is how you export a single scene from a multi-scene timeline, or a specific beat range for a client review.

## Loop

The **loop toggle** (in the Preview Monitor's transport bar) makes playback restart at the in point when it reaches the out point. Useful for tightening a transition or watching a tricky cut on repeat.

Loop respects your current in/out range — if you want to loop the whole timeline, make sure the in/out markers cover it.

## Speed control

The Preview Monitor has a speed selector: **0.25x, 0.5x, 1x, 2x, 4x**. It affects preview playback only — it does not change the exported file's timing.

Slower speeds are useful for auditioning fast cuts and catching sync issues. Higher speeds let you review a long scene quickly before committing to export.

## Other keyboard shortcuts

| Key                    | Action                        |
| ---------------------- | ----------------------------- |
| **Space**              | Toggle play/pause             |
| **Left / Right arrow** | Step one frame back / forward |
| **Delete**             | Remove the selected clip      |
| **Escape**             | Close the full-screen editor  |
| **+ / −**              | Zoom the timeline in / out    |

## Related

<Columns cols={2}>
  <Card title="Timeline Editor Overview" href="/user/timeline/editor-overview">
    The editor's layout — Preview, Inspector, and track stack.
  </Card>

  <Card title="Tracks" href="/user/timeline/tracks">
    The five tracks and how clips populate them.
  </Card>

  <Card title="Export Formats" href="/user/export/export-formats">
    PDF Storyboard, ZIP Frames, and MP4 Animatic — and how in/out affects the MP4.
  </Card>
</Columns>

## FAQ

**Why does JKL feel slow the first time?**
It's a tap-to-accelerate system. Tap **L** once for 1x, twice for 2x, three times for 4x. It's designed for precision, not speed — once you get used to it, you'll never go back to a play button.

**I set an in point but nothing visually changed.**
The in point shows as a small marker on the timecode ruler. Check you scrubbed before pressing **I** — setting it at time zero matches the default, so no visual change is expected.

**Can I set in/out points without the keyboard?**
Yes. Open the Inspector with nothing selected; it shows **In Point** and **Out Point** numeric fields you can edit directly.

**Does snap grid snap to frames or to seconds?**
Seconds, by default — specifically half-seconds. The grid is intended for story timing, not frame-accurate editing.

**Can I shuttle past the end of the timeline?**
No. Playback stops at the last clip's end. Use **End** to jump there instantly.

**What's the difference between preview speed and clip speed?**
Preview speed is 0.25x–4x for watching. Clip speed (slow motion, fast forward) is a separate per-clip property in the Inspector — it affects the exported video.