@data-slot/slider

Headless slider component for vanilla JavaScript. Supports single value and range sliders with full keyboard navigation and ARIA compliance.

Installation

bun add @data-slot/slider
# or
npm install @data-slot/slider

Usage

HTML Structure

<!-- Single value slider -->
<div data-slot="slider" data-default-value="50">
  <div data-slot="slider-track">
    <div data-slot="slider-range"></div>
  </div>
  <div data-slot="slider-thumb"></div>
</div>

<!-- Optional control wrapper -->
<div data-slot="slider" data-default-value="50">
  <div data-slot="slider-control">
    <div data-slot="slider-track">
      <div data-slot="slider-range"></div>
    </div>
    <div data-slot="slider-thumb"></div>
  </div>
</div>

<!-- Range slider (two thumbs) -->
<div data-slot="slider" data-default-value="25,75">
  <div data-slot="slider-track">
    <div data-slot="slider-range"></div>
  </div>
  <div data-slot="slider-thumb"></div>
  <div data-slot="slider-thumb"></div>
</div>

JavaScript

import { create, createSlider } from "@data-slot/slider";

// Auto-discover and bind all [data-slot="slider"] elements
const controllers = create();

// Or target a specific element
const slider = createSlider(element, {
  defaultValue: 50,
  min: 0,
  max: 100,
  step: 1,
  thumbAlignment: "edge",
  onValueChange: (value) => console.log("Changed:", value),
  onValueCommit: (value) => console.log("Committed:", value),
});

// Programmatic control
slider.setValue(75);
console.log(slider.value); // 75

// Cleanup
slider.destroy();

API

Initialization

create(scope?)

Find and bind uninitialized [data-slot="slider"] descendants of scope (defaults to document). Returns SliderController[] for newly bound roots. To initialize the scope element itself, use createSlider.

import { create } from "@data-slot/slider";

const controllers = create();

createSlider(root, options?)

Create a SliderController for one root element. JavaScript options take precedence over the corresponding data attributes. Calling this again for a bound root returns its existing controller; destroy it before rebinding with new options.

import { createSlider } from "@data-slot/slider";

const controller = createSlider(element, {});

Slots

Runtime Slots

• slider - Root element that manages the value, bounds, orientation, and disabled state.
• slider-control - Optional interaction wrapper around the track and thumbs. When omitted, the track's parent is used, typically the root.
• slider-track - Required track used to measure pointer position and lay out the range and thumbs.
• slider-range - Optional filled portion of the track; its position and size follow the selected value or range.
• slider-thumb - Required draggable control with slider semantics and keyboard support. Use one for a single value or two for a range; two thumbs enable range mode.

Data Attributes

Options

JavaScript options take precedence over root data attributes.

Controller

Events

Outbound Events

Listen for these events on the root element.

Inbound Events

Dispatch these events on the root element.

// Listen for changes
root.addEventListener("slider:change", (e) => {
  console.log("Value:", e.detail.value);
});

// Set value from outside
root.dispatchEvent(new CustomEvent("slider:set", {
  detail: { value: 50 }
}));

// Set range value
root.dispatchEvent(new CustomEvent("slider:set", {
  detail: { value: [25, 75] }
}));

Note: Blocked when slider is disabled.

Deprecated Shapes

The following shapes are deprecated and will be removed in v1.0:

// Deprecated: bare number
root.dispatchEvent(new CustomEvent("slider:set", {
  detail: 50
}));

// Deprecated: bare array
root.dispatchEvent(new CustomEvent("slider:set", {
  detail: [25, 75]
}));

Use { value: ... } instead.

Styling

The component sets data attributes and inline styles for CSS hooks:

/* Root state */
[data-slot="slider"][data-orientation="horizontal"] { ... }
[data-slot="slider"][data-orientation="vertical"] { ... }
[data-slot="slider"][data-disabled] { ... }
[data-slot="slider"][data-dragging] { ... }

/* Parts mirror shared state for shadcn/Base-style selectors */
[data-slot="slider-track"][data-orientation="horizontal"] { ... }
[data-slot="slider-track"][data-orientation="vertical"] { ... }
[data-slot="slider-range"][data-orientation="horizontal"] { ... }
[data-slot="slider-range"][data-orientation="vertical"] { ... }
[data-slot="slider-track"][data-disabled] { ... }
[data-slot="slider-range"][data-disabled] { ... }
[data-slot="slider-thumb"][data-orientation="horizontal"] { ... }
[data-slot="slider-thumb"][data-orientation="vertical"] { ... }
[data-slot="slider-thumb"][data-disabled] { ... }

/* Thumb positioning (set automatically) */
[data-slot="slider-thumb"] {
  position: absolute;
  /* --position: X%; inset-inline-start/top or bottom/left are applied inline */
  /* translate is applied inline to center the thumb on the resolved visual position */
}

/* Range thumbs expose their index */
[data-slot="slider-thumb"][data-index="0"] { ... }
[data-slot="slider-thumb"][data-index="1"] { ... }

/* Range positioning (set automatically) */
[data-slot="slider-range"] {
  /* horizontal: relative + inset-inline-start/width */
  /* vertical: absolute + bottom/height */
}

/* Thumb dragging state */
[data-slot="slider-thumb"][data-dragging] { ... }

slider-track, slider-range, and slider-thumb also get Base-style inline layout styles from the controller. The runtime owns the track's position: relative, the range's start/size positioning, and the thumb's absolute position / translate, so authors only need to supply visual styles unless they intentionally want to override that layout behavior.

When thumbAlignment is "edge" or "edge-client-only", the runtime measures the track and thumb size to keep the thumb inside the visible track. In those modes, --position and the range start/size vars represent rendered layout positions rather than raw value percentages.

Thumb Alignment

By default, slider thumbs are centered on the active value. That means the thumb can extend beyond the track when the value is at min or max.

Use thumbAlignment or data-thumb-alignment to change that behavior:

• "center" - Default. The thumb is centered on the value and may overflow the track edges.
• "edge" - Insets the thumb so its edge aligns with the track edge at min and max.
• "edge-client-only" - Accepted for Base UI API parity. In this vanilla package it behaves the same as "edge".

<div data-slot="slider" data-default-value="25" data-thumb-alignment="edge">
  <div data-slot="slider-track">
    <div data-slot="slider-range"></div>
  </div>
  <div data-slot="slider-thumb"></div>
</div>

createSlider(element, {
  defaultValue: 25,
  thumbAlignment: "edge",
});

Keyboard Navigation

Accessibility

Each thumb element receives:

• role="slider"
• tabindex="0"
• aria-valuemin / aria-valuemax / aria-valuenow
• aria-orientation
• aria-disabled (when disabled)
• aria-label (from data-label or auto-generated for range)

slider-track, slider-range, and slider-thumb also mirror the root's data-orientation and data-disabled attrs for styling. slider-control is optional; when omitted, the root acts as the interactive control surface.

License

MIT