Tabs
Base UI Tabs (roving focus, arrow-key nav, a11y) marked with the library's one "you are here": a 2px lit rail slides under the open tab, over a hairline baseline. Labels stay on the chassis. sound.select on change. Compound API.
Feel Picking a tab slides a thin lit rail under its label with a soft click; the other labels stay quiet on the chassis.
Preview
Or let the agent fetch it: get_component("tabs") on the Echo MCP server.
Installation
First time? Run npx echo-ui-cli init once — it sets the project up, and add refuses to run before it.
At a glance
- Version
- 0.3.0
- Weight
- 1.3 KB · 42.5 KB with what it imports · 1.0 KB of CSS (minified and gzipped; React not counted)
- Needs
- @base-ui/react, gsap, size (Echo, brought with it)
- Keyboard
- Renders the ARIA tabs pattern:
Tabs.Listis atablist, eachTabs.Tabatabwitharia-selected, eachTabs.Panelatabpanellabelled by its tab. - Arrow keys move focus between tabs and wrap at the ends; Enter or Space opens the focused tab. Pass
activateOnFocustoTabs.Listto open tabs as focus moves. - The open tab is marked by a lit rail and full-strength label text, not by colour alone.
- Renders the ARIA tabs pattern:
- Reduced motion
- The rail jumps to the new tab instead of sliding.
- Sound
selectwhen the open tab changes. Silent without aSoundProvider.
Usage
import { Tabs } from "@/echo/tabs";
<Tabs defaultValue="meter">
<Tabs.List aria-label="Track view">
<Tabs.Tab value="meter">Meter</Tabs.Tab>
<Tabs.Tab value="log">Log</Tabs.Tab>
</Tabs.List>
<Tabs.Panel value="meter">Levels</Tabs.Panel>
<Tabs.Panel value="log">History</Tabs.Panel>
</Tabs>Composition
Tabs
Tabs.List
Tabs.Tab
Tabs.PanelExamples
Basic
List of tabs + matching panels.
<Tabs defaultValue="a">
<Tabs.List>
<Tabs.Tab value="a">Meter</Tabs.Tab>
<Tabs.Tab value="b">Log</Tabs.Tab>
</Tabs.List>
<Tabs.Panel value="a">…</Tabs.Panel>
<Tabs.Panel value="b">…</Tabs.Panel>
</Tabs>Sizes
`sm` for a card's or a panel's own views, `lg` for the tabs a whole page is built around.
<Tabs defaultValue="day">
<Tabs.List size="sm" aria-label="Chart range">
<Tabs.Tab value="day">Day</Tabs.Tab>
<Tabs.Tab value="week">Week</Tabs.Tab>
</Tabs.List>
</Tabs>Accessibility
- Renders the ARIA tabs pattern:
Tabs.Listis atablist, eachTabs.Tabatabwitharia-selected, eachTabs.Panelatabpanellabelled by its tab. - Arrow keys move focus between tabs and wrap at the ends; Enter or Space opens the focused tab. Pass
activateOnFocustoTabs.Listto open tabs as focus moves. - Name the list:
aria-labelonTabs.List, oraria-labelledbypointing at a visible heading. - The open tab is marked by a lit rail and full-strength label text, not by colour alone.
Tested against WCAG 2.2 AA on every release:
axe— No axe violations, in the component's own gallery and on its page.keyboard— Every action is reachable and operable from the keyboard alone.focus-visible— Focus is visible on every focusable part, in normal and forced-colors mode.forced-colors— State stays visible when the look's colours are replaced by the system's.target-size— Every target's real hit area is at least 24×24px, at every density.reflow— Content reflows into 320px and survives a doubled text size.
Not covered: screen-reader: not yet verified by a person. Everything above is a machine check; a person has not yet driven this component with a screen reader.
Motion & sound
- Motion tokens
--echo-duration-sweep,--echo-duration-swap- Reduced motion
- The rail jumps to the new tab instead of sliding.
- Sound
selectwhen the open tab changes. Silent without aSoundProvider.
Props
Compound API with one prop of its own: size on Tabs.List (sm 32, md 44, lg 60px, the control heights; defaults to the surrounding SizeProvider, else md; on a touch screen sm grows to 44px). Otherwise <Tabs> takes Base UI Tabs.Root's props (value, defaultValue, onValueChange, orientation), and Tabs.List / Tabs.Tab / Tabs.Panel take theirs — Tabs.Tab and Tabs.Panel are paired by value. Echo adds the skin and the select sound without narrowing the API, so a table here would only restate Base UI's.
Anti-patterns
- Every Tabs.Tab needs a matching Tabs.Panel with the same value.
- Do not put many tabs in a segmented control — it is for a few peer views, not navigation.
Changelog
- The drawn device (
echo-ui-core,echo-ui-cli, every component that draws its own material). A seed's newrendersetting ismolded(Echo as it has always been: plastic lit by one key light) ordrawn: the same parts drawn in the ink, the way a spec sheet draws a key. Every part is outlined at one weight (--echo-line,--echo-line-width), hollow on the body; a raised part stands on a hard ink edge as deep as it rises and travels down it when pressed; a recess is an outline drawn inside; something floating stands on a deeper edge. There's no light, so no gloss, no soft shadow and no glow: what a molded device lights (an LED, the rail, a readout, the focus ring, a fader's knob, a radio's pip) is solid ink, and a low-emphasis action is its label underlined. In black and white (the accent the ink) "on" is solid ink and what's drawn on it inverts: a switch's thumb turns paper, a fader's knob is knocked out with a paper ring. The primary key is the paper key that stands highest, on an ink edge twice as deep as a neutral one's, the way a spec sheet draws its CTA. The accent stays the seed's own colour as a flat fill for what's on (a chosen segment, a checked box, a slider's travel, a switch that's on), so an acid highlighter is acid, not the olive a molded device holds it to; what's drawn on it is the ink, or the body when the accent is too deep for the ink. Pressing, travel, sound, what each material is for and every contrast guarantee are unchanged.npx echo-ui-cli style set render drawnturns it on; a style sets it in its seed; the published style and config schemas describe it, andDESIGN.mdsays how a drawn device builds. A molded device renders exactly as before: every line is 0px wide there, and each drawn value a component reads (--echo-drawn-fill,-on-fill,-ink,-rule,-glass,-hollow,-decoration) isinitial, so it falls back to what the component always drew. HardwareButton's bed is the one new hand-tuned shadow: a drawn key stands on its own edge instead of being drawn in a recess. - Every item needs
echo-ui-core0.3.0 (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 declaresecho-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), thennpx 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. - The 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, andvalues.polarityon 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 newaccent-inkrole. The primary cap is the same cap as a dark device's, the accent with a light label: its label is the newprimary-cap-inkrole, 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 newpour-*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-stockand--echo-paper-inkinstead, 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-inkand--echo-accent-inkthe same way; every rail is drawn in the glow, and every focus ring, theringrecipes included, in the ink.style usewears a light style now, andstyle checksays 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. Tabsjoin the size scale.sizeonTabs.Listmakes each tab 32, 44 or 60px tall, the same as a field or a button of that size, and it follows a surroundingSizeProvider. The default is 44px, a full target;smsuits a card's own views and grows to 44px on a touch screen.echo-tabsis fully documented — usage, composition, accessibility, motion & sound and a one-line feel — the first item written to the new component page template.- Components 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. - Comments 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'sengraved/captionchecks andStatusDot's missing-label check) also dropped the ticket code at the end of the message.echo-ui diffwill show changes in most items; none of them are to code. - An 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 "
MenuandSheetare unchanged here" filed itself as a change to Menu and Sheet — which it really had. - The agent brief says Echo has not shipped.
llms.txtand the MCP server's instructions led withnpx 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. Affectsall componentsonly in what the brief says about installing them; no item's props, CSS or rendered semantics change. - Echo's home is
echo-ui.com. The registry, the docs and the packages all move to it fromecho.nawwara.studio. Nothing was published under the old host, so noecho.jsonanywhere points at it and there is nothing to migrate — this is the last release where that is true. - Descriptions that described an older look.
Tabs(a lit rail, not a lit cap),Select(CSS fades, not a GSAP exit), andBadge,Segmented,SelectandField, which named the default seed's raspberry instead of the accent. - Weights, 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 withecho-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). - A 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. - On a phone, a tapped part no longer stays lit (BUG-143). A phone leaves what you tapped under
:hoveruntil 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. - Content 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,SegmentedandStepsas flex items,EmptyState's grid columns, andAvatar's fixed-pixel disc all gave way;Panelcounts 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.