Goo Switch

New

A switch whose thumb is a drop of liquid: it trails a tail when it moves and stretches over the edge when you pull it too far.

Install it in one line

npx devignerui add goo-switch

Writes components/ui/goo-switch.tsx and lists what it needs.

First time here

npx devignerui init

Or by hand

Needs React 18 or 19 and Tailwind CSS v4.
Install the dependencies.
npm i cn motion devignerui
Paste the source from into components/ui/goo-switch.tsx.

Usage

import { useState } from "react";
import { GooSwitch } from "@/components/ui/goo-switch";

export function Example() {
  const [on, setOn] = useState(true);
  return (
    <GooSwitch
      checked={on}
      onCheckedChange={setOn}
      aria-label="Wi-Fi"
      size="lg"
    />
  );
}

Custom composition

<GooSwitch checked={on} onCheckedChange={setOn} aria-label="Wi-Fi" size="lg" inset={2} sling={false} />

In a form

Submits "yes" under newsletter while on, and must be on to submit.

import { GooSwitch } from "@/components/ui/goo-switch";

export function Signup() {
  return (
    <form action="/api/signup" className="flex items-center gap-3">
      <span id="newsletter-label" className="text-sm">Send me the newsletter</span>
      <GooSwitch name="newsletter" value="yes" required aria-labelledby="newsletter-label" />
      <button type="submit">Sign up</button>
    </form>
  );
}

Labelled setting

Keep the state in React and label the switch with the text beside it.

import { useState } from "react";
import { GooSwitch } from "@/components/ui/goo-switch";

export function WifiSetting() {
  const [on, setOn] = useState(true);
  return (
    <div className="flex items-center justify-between gap-6">
      <span id="wifi-label" className="text-sm font-medium">Wi-Fi</span>
      <GooSwitch checked={on} onCheckedChange={setOn} aria-labelledby="wifi-label" />
    </div>
  );
}

Every prop

checked-

boolean

Controlled state.

defaultCheckedfalse

boolean

Initial state.

onCheckedChange-

function

Fires with the new state.

disabledfalse

boolean

Disables interaction.

sizemd

"sm" | "md" | "lg"

Track height: 24, 32 or 40px.

inset4

number

Gap around the thumb, in 32nds of the track height (1 to 10).

stretchtrue

boolean

Dragging past an end spreads the thumb over the edge.

sling0.5

number | false

Stretch (0 to 1) past which a release slings to the other side; false never slings.

trail3.2

number

Droplet tail length on a toggle; 0 hides it.

name-

string

Form field name; submitted when on.

valueon

string

Value submitted under name.

requiredfalse

boolean

Blocks form submission while off.

classNames-

GooSwitchClassNames

Slot classes.

How to use it

The live demo is a switch that is on. Click it and the thumb shrinks to a drop, runs to the other end with a tail behind it and settles back into a pill; drag it past either end and it spreads over the edge, and letting go there slings it to the opposite side.

When to use it

A single on/off setting that applies right away, where the switch itself is part of the product's personality.
Settings screens and toolbars with only a few toggles, so the motion stays a treat.

When to reach for something else

Choices that only apply after a Save button. Use a checkbox.
Dense tables or long settings lists, where every row moving like liquid gets tiring.

Keyboard

Space / Enter: Toggles the switch.
Tab: Moves focus to and from the switch.

Accessibility

Renders a native button with role="switch" and aria-checked, so screen readers announce it as a switch and its state.
It has no visible label of its own. Pass aria-label, or aria-labelledby pointing at the text next to it.
The form checkbox is hidden from assistive tech and the tab order; when validation lands on it, focus moves to the switch.
Honors prefers-reduced-motion and an ancestor <MotionConfig reducedMotion="always">, so an in-app motion switch works too.

Theming

On, the track uses var(--primary); off, a mix of var(--muted-foreground) and var(--background). The thumb is white in both themes.
Hover and press wash the track toward var(--background), so it follows dark mode.
size picks a 24, 32 or 40px track; a height class in className overrides it, and the width always follows at 62:32. classNames targets root and svg.
inset sets the gap around the thumb in 32nds of the track height; the thumb grows into whatever the gap gives up.
trail sets how long the droplet tail is on a toggle, and 0 turns it off for a plainer switch.

Edge cases

A click toggles on release. A drag ends on the side the thumb was let go on.
A drag pulled past sling (half the stretch by default) slings the thumb to the other side: pulled past the right end it turns off, past the left end it turns on. sling={false} turns this off, and stretch={false} stops the thumb at the ends altogether.
With name set, a hidden checkbox submits value under name while the switch is on, and nothing while it is off, the same as a checkbox. required blocks submission while off, and a form reset returns it to defaultChecked.
The pointer is captured while pressed, so the drag keeps working outside the switch.
Setting checked from outside moves the thumb with the same droplet motion as a click.

Troubleshooting

Dragging the switch scrolls the page on a phone.

The switch sets touch-action: none on itself. If a parent handles the gesture first (a carousel or a sheet), stop propagation of pointerdown on the switch.

My form does not receive the switch value.

Pass name. Without it no form field is rendered. Like a checkbox, the field is only sent while the switch is on.

The component renders with no background or the wrong colors.

Colors use the standard shadcn/ui tokens only (background, foreground, primary, secondary, muted, accent, border, input, ring, destructive), so a project set up with shadcn/ui needs nothing extra and the component follows its theme, dark mode included. Without shadcn/ui, define those CSS variables for :root and .dark and map them in your Tailwind v4 @theme, or run npx shadcn init.

Some of these designs take cues from interfaces we've admired around the web. If one started as your idea and you'd like credit, message us on X @devignerui and we'll add it.