---
title: Split Panes
description: Working with split panes in cmux
---

# Split Panes

cmux supports splitting terminal panes within a tab, allowing you to view multiple terminals side by side.

## Creating Splits

### Keyboard Shortcuts

| Shortcut | Action |
|----------|--------|
| **⌘D** | Split right |
| **⌘⇧D** | Split down |

### Using the CLI

```bash
# Split in a specific direction
cmux new-split right
cmux new-split down
cmux new-split left
cmux new-split up
```

## Navigating Splits

### Keyboard

Use **⌘⌥** + arrow keys to move between splits:

| Shortcut | Action |
|----------|--------|
| **⌘⌥←** | Focus left pane |
| **⌘⌥→** | Focus right pane |
| **⌘⌥↑** | Focus pane above |
| **⌘⌥↓** | Focus pane below |

### CLI

```bash
# List all panes in current tab
cmux list-panels

# Focus a specific pane
cmux focus-panel --panel <panel-id>
```

## Closing Splits

- **⌘W** - Close the focused pane
- If only one pane remains, **⌘W** closes the tab

## Visual Styling

Unfocused panes are visually distinguished to help you identify the active pane.

### Configuration

In your Ghostty config:

```ini
# Dim unfocused panes (0.0 = fully dimmed, 1.0 = no dimming)
unfocused-split-opacity = 0.7

# Background fill for unfocused panes
unfocused-split-fill = #1e1e2e

# Color of the divider between panes
split-divider-color = #45475a
```

## Split Layout

cmux uses a binary split tree structure:

- Each split creates two child panes
- Nested splits create a tree of panes
- Each pane has a unique `panel-id` for CLI access

### Example Layout

```
┌────────────────────────────────┐
│           Tab 1                │
├──────────────┬─────────────────┤
│              │     Pane 2      │
│   Pane 1     ├─────────────────┤
│              │     Pane 3      │
└──────────────┴─────────────────┘
```

This layout is created by:
1. Split right → Pane 1 | Pane 2
2. Focus Pane 2
3. Split down → Pane 2 | Pane 3

## Sending Input to Specific Panes

With the CLI, you can send input to specific panes:

```bash
# Send text to a specific pane
cmux send-panel --panel <panel-id> "echo hello"

# Send a keypress to a specific pane
cmux send-key-panel --panel <panel-id> enter
```