Collapsible

Preview

Installation

npx echo-ui-cli add collapsible

At a glance

Version

0.3.0

Weight

486 B · 7.8 KB with what it imports · 863 B of CSS (minified and gzipped; React not counted)

Needs

@base-ui/react

Keyboard

Enter and Space open and close it.

Reduced motion

The panel opens and closes at once; the chevron turns without moving.

Sound

tap as it opens or closes, inside a SoundProvider.

Usage

import { Collapsible } from "@/echo/collapsible";

<Collapsible title="Advanced settings">{content}</Collapsible>

Composition

Collapsible → a trigger row and a panel (Base UI Collapsible)

Examples

<Collapsible title="Advanced settings">
  <NumberField label="Buffer" defaultValue={256} />
</Collapsible>

<Collapsible title="Details" open={open} onOpenChange={setOpen}>{details}</Collapsible>

Accessibility

• The row is a button with aria-expanded, controlling the panel.
• Enter and Space open and close it.
• Closed content is hidden="until-found": find-in-page can match it and opens the panel.

Motion & sound

Motion tokens

pop

Reduced motion

The panel opens and closes at once; the chevron turns without moving.

Sound

tap as it opens or closes, inside a SoundProvider.

Props

Anti-patterns

• Never put the only copy of something required inside a closed Collapsible.
• Don't stack several to build a list: that's an Accordion, which keeps them as one group.

Changelog

• v0.3.0 · 2026-10-12 · ChangedEvery item needs echo-ui-core 0.3.0 (all components). The drawn device, readability past AA and the design tests live in core, and the components that use them are built against it, so each item now declares echo-ui-core >=0.3.0 <0.4.0. Update core with the items: npm install echo-ui-core@^0.3.0 (or your package manager's), then npx echo-ui-cli update. An item whose files didn't change is the same code under a new version; the 0.2.0 files stay published.
• v0.2.0 · 2026-10-04 · AddedThe light device (echo-ui-core, echo-ui-cli). Echo can be light: a pale chassis makes a device molded in light plastic, like a white calculator or a cream radio, and a dark one makes the device Echo has always been. There's no setting and no mode to switch; the chassis decides (devicePolarity, and values.polarity on the theme). On a light device the page is light: its ground, the well, is the body barely set in. Caps get their own ladder, a step lighter than the body with a lit rim that stops short of white, so they keep their bevel; undersides and seams are shaded darker; dim text moves toward the ground by the same step as on a dark device, and reads about 6:1 on it. Screens are paper glass printed in ink, because a glow on a pale body is a smudge. What's lit (an LED, the current rail) is still the accent, held to 3:1 on every ground, so on is brighter than off; the text it prints (a readout, a count, a current tab) and the focus ring are the accent's ink, a step deeper and held to AA, in the new accent-ink role. The primary cap is the same cap as a dark device's, the accent with a light label: its label is the new primary-cap-ink role, and progress cells, loader dots and a meter's fill, the same plastic, read 3:1 on the page. A neutral cap or a slider that fills with it under its own dark label fills with the new pour-* roles, the accent's pale stops. Shadows are drawn at half their weight, in a deep colour of the body's own hue (--echo-cast-ink) instead of black. Every guarantee holds as it does on a dark device, and the contrast sweep now runs on light bodies too. A dark seed makes exactly the theme it did before, and the new roles equal the ones they stand for there. The components that mixed a recess toward black, painted paper in the text colour or lit a pillow of light with it read the theme's new --echo-shade-ink, --echo-paper-stock and --echo-paper-ink instead, with the old value as the fallback, and a reflective screen reads --echo-screen-*; the components that print a lit label read --echo-primary-cap-ink and --echo-accent-ink the same way; every rail is drawn in the glow, and every focus ring, the ring recipes included, in the ink. style use wears a light style now, and style check says which device a style makes. A dark screen tint on a light body is still refused: one text colour can't serve both, and the theme says so.
• v0.2.0 · 2026-10-04 · AddedSix containers: Card, Item, Stack & Grid, Collapsible, ScrollArea and Link. The pieces every screen is laid out with, so nobody spaces a card by hand. All six are closed: their slots and spacing are props, not a className. - Card is a Panel with an anatomy (media, a header with one action, a body, a footer whose controls are sm) and size for its padding. With href or onClick the whole card is one link or button, named by its title, with one focus ring; it lifts as you reach for it, sinks a pixel as you press and sends Panel's ripple out from your finger. - Item is the list row: media, title, description, trailing content, ruled by a hairline. swipeActions sit behind it: swipe it and they slide into view, and Tab reaches each one, sliding the row open the same way, so the gesture is never the only way in. - Stack & Grid (echo-layout) take gaps as steps on the space scale; a row wraps and a Grid's columns never get wider than the screen. - Collapsible is one disclosure on its own, in Accordion's ruled style; closed content stays findable with find-in-page, which opens it. - ScrollArea scrolls inside itself with a groove and a molded thumb, shades whichever edge has more to see, and is a named region the keyboard can scroll. - Link keeps the words in the text colour and draws the accent as the underline (accent text on the chassis is under AA); external says it opens a new tab; render takes your router's link.
• v0.2.0 · 2026-10-04 · ChangedComponents whose shadow is a recipe read it by name. 71 shadows in 54 items now say var(--echo-shadow-<name>, <the same shadow>), so they look exactly as they did (every docs page was compared before and after) and follow a theme's recipes. Scope declares the recipes that read the accent again, so a Scope's own colour still reaches its focus rings and glows, and reflective screens do the same for theirs. Shadows that move with their part (a cap's drop as it's pressed) stay in the component.
• v0.2.0 · 2026-10-04 · ChangedComments only, no behaviour change. Comments in the component source used to cite documents, milestones and ticket numbers from Echo's own planning, none of which exist in your project. The citations are gone and the sentences around them stay. Where a comment was only a citation, it now says what it meant. Three development warnings (HardwareButton's engraved/caption checks and StatusDot's missing-label check) also dropped the ticket code at the end of the message. echo-ui diff will show changes in most items; none of them are to code.
• v0.2.0 · 2026-10-04 · ChangedAn item's version is now a function of declared data, not of how the changelog is formatted. The version an item ships under is published once and never rewritten, and it used to be inferred from prose: a regex for a bolded "Breaking" run across the whole unreleased section, and attribution by "does a bullet mention this name in backticks". One breaking entry therefore moved every item that changed that cycle, and an entry explaining that "Menu and Sheet are unchanged here" filed itself as a change to Menu and Sheet — which it really had.
• v0.2.0 · 2026-10-04 · ChangedThe agent brief says Echo has not shipped. llms.txt and the MCP server's instructions led with npx echo-ui-cli init, and that name on npm is a reserved stub with no executable — so a model following the brief wrote an install step that fails with npx's own error. The brief now opens with the caveat, and the docs carry it on every surface that shows a command. One switch (CLI_RELEASED) silences all of them at launch, and a test refuses to let one move without the others. Affects all components only in what the brief says about installing them; no item's props, CSS or rendered semantics change.
• v0.2.0 · 2026-10-04 · ChangedEcho's home is echo-ui.com. The registry, the docs and the packages all move to it from echo.nawwara.studio. Nothing was published under the old host, so no echo.json anywhere points at it and there is nothing to migrate — this is the last release where that is true.
• v0.2.0 · 2026-10-04 · ChangedWeights, line heights, letter-spacing, z-index, border widths and icon sizes come from the theme scales in all components, with the old value as a fallback, so components keep working with echo-ui-core@0.0.1. Strays moved to the nearest step: most by under a pixel; HardwareButton icons are 14/16/20px (were 15/17/19).
• v0.2.0 · 2026-10-04 · FixedA light device's recesses keep the body's hue in Chromium (echo-ui-core, BUG-166). Chromium drops the hue of a colour under 0.02 chroma when it mixes in oklch, and draws the mix at hue 0, a rose. A light device's plastic is that grey, so on a lilac body every field, track and rail was pink. A mix made only of greys is made in oklab now, which has no hue to lose; a mix with an accent in it stays in oklch. On a dark device nothing you can see changes.
• v0.2.0 · 2026-10-04 · FixedOn a phone, a tapped part no longer stays lit (BUG-143). A phone leaves what you tapped under :hover until the next tap, so a table row stayed shaded and a trigger stayed lit after the finger lifted. Hover styles now apply only where there's a pointer that can hover (@media (hover: hover)), in all 23 components that had one. Checked, active and focus styles that shared a rule with them still apply everywhere.
• v0.2.0 · 2026-10-04 · FixedContent now reflows into a 320px screen (400% zoom) and survives a doubled browser text size (WCAG 1.4.10, 1.4.4), across all components. Select's 180px floor, NumberField's readout, Segmented and Steps as flex items, EmptyState's grid columns, and Avatar's fixed-pixel disc all gave way; Panel counts its padding inside a width you set (box-sizing: border-box), so a <Panel style={{ width: 220 }}> is now 220px wide overall rather than 260px.