React Split Pane v3

Modern, accessible, TypeScript-first split pane component for React.

Live Examples

✨ Features

• 🪝 Hooks-based - Built with modern React patterns
• 📘 TypeScript - Full type safety out of the box
• ♿ Accessible - Keyboard navigation, ARIA attributes, screen reader support
• 📱 Touch-friendly - Full mobile/tablet support
• 🎯 Flexible - Controlled/uncontrolled modes, nested layouts, 2+ panes
• 🪶 Lightweight - < 5KB gzipped
• ⚡ Performant - RAF-throttled resize, optimized renders
• 🎨 Customizable - Full styling control

Installation

npm install react-split-pane

# or
yarn add react-split-pane

# or
pnpm add react-split-pane

Quick Start

import { SplitPane, Pane } from 'react-split-pane';

function App() {
  return (
    <SplitPane direction="horizontal">
      <Pane minSize="200px" defaultSize="300px">
        <Sidebar />
      </Pane>
      <Pane>
        <MainContent />
      </Pane>
    </SplitPane>
  );
}

Note: SplitPane requires its container to have explicit dimensions. The component uses width: 100% and height: 100%, so the parent element must have a defined size. For vertical splits, ensure the parent has an explicit height (e.g., height: 100vh). See Container Sizing for details.

Basic Usage

Horizontal Split (Side-by-Side)

<SplitPane direction="horizontal">
  <Pane defaultSize="25%">
    <LeftPanel />
  </Pane>
  <Pane>
    <RightPanel />
  </Pane>
</SplitPane>

Vertical Split (Top-Bottom)

<SplitPane direction="vertical">
  <Pane defaultSize="100px">
    <Header />
  </Pane>
  <Pane>
    <Content />
  </Pane>
</SplitPane>

Controlled Mode

function App() {
  const [sizes, setSizes] = useState([300, 500]);

  return (
    <SplitPane onResize={setSizes}>
      <Pane size={sizes[0]} minSize="200px">
        <Sidebar />
      </Pane>
      <Pane size={sizes[1]}>
        <Main />
      </Pane>
    </SplitPane>
  );
}

Nested Layouts

<SplitPane direction="vertical">
  <Pane defaultSize="60px">
    <Header />
  </Pane>

  <SplitPane direction="horizontal">
    <Pane defaultSize="250px" minSize="150px">
      <Sidebar />
    </Pane>

    <SplitPane direction="vertical">
      <Pane>
        <Editor />
      </Pane>
      <Pane defaultSize="200px">
        <Console />
      </Pane>
    </SplitPane>
  </SplitPane>
</SplitPane>

Advanced Features

Persistence

The usePersistence hook saves and restores pane sizes to localStorage (or sessionStorage):

import { usePersistence } from 'react-split-pane/persistence';

function App() {
  const [sizes, setSizes] = usePersistence({ key: 'my-layout' });

  return (
    <SplitPane onResize={setSizes}>
      <Pane size={sizes[0] || 300}>
        <Sidebar />
      </Pane>
      <Pane size={sizes[1]}>
        <Main />
      </Pane>
    </SplitPane>
  );
}

usePersistence Options

Option	Type	Default	Description
key	string	Required	Storage key for persisting sizes
storage	Storage	localStorage	Storage backend (localStorage or sessionStorage)
debounce	number	300	Debounce delay in ms before saving

// Use sessionStorage instead of localStorage
const [sizes, setSizes] = usePersistence({
  key: 'my-layout',
  storage: sessionStorage,
  debounce: 500,
});

Snap Points

<SplitPane
  snapPoints={[200, 400, 600]}
  snapTolerance={20}
>
  {/* panes */}
</SplitPane>

Custom Divider

function CustomDivider(props) {
  return (



      <GripIcon />



  );
}

<SplitPane divider={CustomDivider}>
  {/* panes */}
</SplitPane>

Keyboard Navigation

The divider is fully keyboard accessible:

• Arrow Keys: Resize by step pixels (default: 10px)
• Shift + Arrow: Resize by larger step (default: 50px)
• Home: Minimize left/top pane
• End: Maximize left/top pane
• Escape: Restore pane sizes to initial state
• Tab: Navigate between dividers

API Reference

SplitPane Props

Prop	Type	Default	Description
direction	'horizontal' \| 'vertical'	'horizontal'	Layout direction
resizable	boolean	true	Whether panes can be resized
snapPoints	number[]	[]	Snap points in pixels
snapTolerance	number	10	Snap tolerance in pixels
step	number	10	Keyboard resize step
onResizeStart	(event) => void	-	Called when resize starts
onResize	(sizes, event) => void	-	Called during resize
onResizeEnd	(sizes, event) => void	-	Called when resize ends
className	string	-	CSS class name
style	CSSProperties	-	Inline styles
divider	ComponentType	-	Custom divider component
dividerClassName	string	-	Divider class name
dividerStyle	CSSProperties	-	Divider inline styles

Pane Props

Prop	Type	Default	Description
defaultSize	string \| number	'50%'	Initial size (uncontrolled)
size	string \| number	-	Controlled size
minSize	string \| number	0	Minimum size
maxSize	string \| number	Infinity	Maximum size
className	string	-	CSS class name
style	CSSProperties	-	Inline styles

Container Sizing

SplitPane uses width: 100% and height: 100% and measures its container via ResizeObserver. The parent container must have explicit dimensions for panes to render correctly.

Common Issue: Invisible Panes

If your pane content doesn't appear, the most common cause is a missing height on the parent container. This is especially true for vertical splits:

// ❌ Won't work - parent has no height
function App() {
  return (



      <SplitPane direction="vertical">
        <Pane>

Top

</Pane>
        <Pane>

Bottom

</Pane>
      </SplitPane>



  );
}

// ✅ Works - parent has explicit height
function App() {
  return (



      <SplitPane direction="vertical">
        <Pane>

Top

</Pane>
        <Pane>

Bottom

</Pane>
      </SplitPane>



  );
}

Solutions

1. Set explicit height on parent (recommended for most cases): css .container { height: 100vh; }

2. Use absolute positioning: css .container { position: absolute; inset: 0; }

3. Use flexbox with flex-grow: css .parent { display: flex; flex-direction: column; height: 100vh; } .container { flex: 1; }

Styling

Default Stylesheet

Import the optional default styles with CSS custom properties:

import 'react-split-pane/styles.css';

Customize via CSS variables:

.my-split-pane {
  --split-pane-divider-size: 8px;
  --split-pane-divider-color: #e0e0e0;
  --split-pane-divider-color-hover: #b0b0b0;
  --split-pane-focus-color: #2196f3;
}

The default styles include dark mode support via prefers-color-scheme.

Basic Styles

.split-pane {
  height: 100vh;
}

.split-pane-divider {
  background: #e0e0e0;
  transition: background 0.2s;
}

.split-pane-divider:hover {
  background: #b0b0b0;
}

.split-pane-divider:focus {
  outline: 2px solid #2196f3;
  outline-offset: -2px;
}

Expanded Hover Area

This classic pattern creates a thin visible divider with a larger grabbable area that reveals on hover:

.split-pane-divider {
  background: #000;
  opacity: 0.2;
  z-index: 1;
  box-sizing: border-box;
  background-clip: padding-box;
}

.split-pane-divider:hover {
  transition: all 0.2s ease;
}

.split-pane-divider.horizontal {
  width: 11px;
  margin: 0 -5px;
  border-left: 5px solid rgba(255, 255, 255, 0);
  border-right: 5px solid rgba(255, 255, 255, 0);
  cursor: col-resize;
}

.split-pane-divider.horizontal:hover {
  border-left: 5px solid rgba(0, 0, 0, 0.5);
  border-right: 5px solid rgba(0, 0, 0, 0.5);
}

.split-pane-divider.vertical {
  height: 11px;
  margin: -5px 0;
  border-top: 5px solid rgba(255, 255, 255, 0);
  border-bottom: 5px solid rgba(255, 255, 255, 0);
  cursor: row-resize;
}

.split-pane-divider.vertical:hover {
  border-top: 5px solid rgba(0, 0, 0, 0.5);
  border-bottom: 5px solid rgba(0, 0, 0, 0.5);
}

Minimal Divider

A subtle single-pixel divider:

.split-pane-divider.horizontal {
  width: 1px;
  margin: 0;
  background: linear-gradient(to right, transparent, #ccc, transparent);
}

.split-pane-divider.vertical {
  height: 1px;
  margin: 0;
  background: linear-gradient(to bottom, transparent, #ccc, transparent);
}

Tailwind CSS & shadcn/ui

React Split Pane works seamlessly with Tailwind CSS and shadcn/ui. See TAILWIND.md for detailed integration examples including custom dividers and CSS variable overrides.

Migration from v0.1.x or v2.x

See MIGRATION.md for detailed migration guide.

Quick changes:

// v0.1.x
<SplitPane split="vertical" minSize={50} defaultSize={100}>


Pane 1




Pane 2


</SplitPane>

// v3
<SplitPane direction="horizontal">
  <Pane minSize="50px" defaultSize="100px">


Pane 1


  </Pane>
  <Pane>


Pane 2


  </Pane>
</SplitPane>

Browser Support

• Chrome/Edge (latest 2 versions)
• Firefox (latest 2 versions)
• Safari (latest 2 versions)
• Mobile browsers (iOS Safari, Chrome Android)

Note: IE11 is not supported. Use v0.1.x for IE11 compatibility.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md.

License

MIT © tomkp