Displaying Hotkeys in Your Svelte UI

Format a hotkey as a label whenever it appears in a menu, button, tooltip, cheat sheet, or shortcut settings panel. getFormatForDisplay returns a function that formats chord strings, including physical ones such as 'Mod+[KeyS]', chord objects, parsed chords, and sequences. Store the hotkey itself, and format it when you render. A label is for reading, not for registering.

A label depends on the user's platform: Mod+S is ⌘ S on macOS and Ctrl+S elsewhere. getFormatForDisplay works wherever your labels render:

Format a hotkey#

Call getFormatForDisplay at the top level of a component's <script>. It returns the function that formats a hotkey:

<script lang="ts">
  import { getFormatForDisplay } from '@tanstack/svelte-hotkeys'

  const formatForDisplay = getFormatForDisplay()
</script>

<button>
  Save <kbd>{formatForDisplay('Mod+S')}</kbd>
</button>

The label is ⌘ S on macOS and Ctrl+S on Windows and Linux. getFormatForDisplay fills in two things for you:

• The platform from the nearest HotkeysProvider, or the detected platform without one.
• The user's keyboard layout, for physical keys, in Chromium browsers. See Label physical keys for the user's keyboard.

Call getFormatForDisplay once, then call the function anywhere in the component, including in markup, {#each} blocks, and $derived. Options go in its second argument. The examples in this guide pass platform, so each one has a single result:

formatForDisplay('Mod+S', { platform: 'mac' }) // '⌘ S'
formatForDisplay('Mod+[KeyS]', { platform: 'mac' }) // '⌘ S'
formatForDisplay({ code: 'KeyS', mod: true }, { platform: 'windows' }) // 'Ctrl+S'
formatForDisplay('Mod+[Digit2]', { platform: 'windows' }) // 'Ctrl+2'

The same label can stand for different hotkeys. Mod+S follows the character S, and Mod+[KeyS] follows the key in the S position. See Match a key's position instead. Labels for positions shorten KeyS to S and Digit2 to 2, keep readable numpad labels, and reuse punctuation and special-key symbols. The extra ISO and JIS keys, which have no US key, use their keycap legends: [IntlBackslash] shows \, [IntlRo] shows \, and [IntlYen] shows ¥. Formatting doesn't change the stored hotkey or guess the user's keyboard layout.

A platform you pass wins over the provider's. On macOS, the label joins modifier symbols with spaces. Windows and Linux use names joined with +. macOS orders modifiers as Control, Option, Shift, Command, so Mod+Shift+S displays as ⇧ ⌘ S, while the hotkey itself stays Mod+Shift+S.

The function accepts hotkeys only, including single keys such as 'Escape' and modifiers on their own such as 'Shift'. A key from a KeyboardEvent, such as a held key, can be outside the key types: pass it as { key }.

Render individual keycaps#

Set parts: true to get one label per key instead of a joined string:

const saveHotkey = 'Mod+[KeyS]'
const parts = formatForDisplay(saveHotkey, { platform: 'mac', parts: true })
// ['⌘', 'S'], one label per <kbd>

With parts omitted or false, the result is a string. A runtime boolean returns string | string[]. Parts keep literal plus keys and ignore separatorToken.

Format sequences#

Pass a sequence to format each step and join the steps with sequenceSeparator, a space by default:

formatForDisplay(['Mod+[KeyK]', 'C'], { platform: 'mac' }) // '⌘ K C'
formatForDisplay(['G', 'G'], { sequenceSeparator: ' → ' }) // 'G → G'
formatForDisplay(['Mod+[KeyK]', 'C'], { platform: 'mac', parts: true })
// [['⌘', 'K'], ['C']], one array of keycaps per step

With parts: true, a sequence returns one array per step, so you can render each step as a group of keycaps. To show the steps a user has pressed so far, see Show sequences in your UI.

Choose symbols and separators#

useSymbols accepts a boolean or separate modifiers and keys settings. Omitted fields default to true. Modifier symbols apply on macOS. Windows and Linux keep modifier names.

formatForDisplay('Shift+[ArrowUp]', {
  platform: 'mac',
  useSymbols: { modifiers: false, keys: true },
  parts: true,
}) // ['Shift', '↑']

formatForDisplay('Mod+[KeyS]', {
  platform: 'mac', useSymbols: false,
}) // 'Cmd+S'

formatForDisplay('Control++', {
  platform: 'windows', separatorToken: ' · ',
}) // 'Ctrl · +'

An empty separator joins labels directly. undefined or null uses the platform default. separatorToken applies within a chord, and sequenceSeparator applies between steps.

Label physical keys for the user's keyboard#

A position, such as [KeyQ], has a fallback label for a US keyboard: Q. On a French AZERTY keyboard, that key is labeled A. Labels from getFormatForDisplay follow the user's keyboard where the browser reports its layout:

<script lang="ts">
  import { getFormatForDisplay } from '@tanstack/svelte-hotkeys'

  const formatForDisplay = getFormatForDisplay()
</script>

<!-- 'W' on QWERTY, 'Z' on AZERTY -->
<kbd>{formatForDisplay('[KeyW]')}</kbd>

• The layout loads after the first label mounts. The first render shows the fallback label, and so does server HTML. The label updates when the layout arrives, and later labels have it at once.
• Only positions change. Hotkeys that follow characters, such as Mod+Q, already show the right key. Matching and recording never use the layout.
• The layout is read again when the window regains focus, because browsers send no event when the user switches layouts.

getKeyboardLayout() returns an object whose reactive layout property holds the loaded layout, or null, for labels you draw yourself, such as an on-screen keyboard. The layout maps each code to the character the key types without modifiers, such as KeyQ to a.

The layout comes from navigator.keyboard.getLayoutMap(). To never call it, set keyboardLayout: false in the provider's defaultOptions:

<HotkeysProvider defaultOptions={{ keyboardLayout: false }}>
  <App />
</HotkeysProvider>

Supply your own layout#

Pass the same kind of map as layoutMap, for a layout your app already knows, such as one the user picked in settings:

const layoutMap = new Map([['KeyQ', 'a']])

formatForDisplay('Mod+[KeyQ]', { platform: 'mac', layoutMap }) // '⌘ A'
formatForDisplay('Mod+Q', { platform: 'mac', layoutMap }) // '⌘ Q'

Any object with get(code): string | undefined works. A layoutMap you pass wins over the loaded layout.

Use keyLabels for your own labels, keyed by physical code or by key name:

formatForDisplay('Mod+[KeyQ]', {
  platform: 'mac', layoutMap, keyLabels: { KeyQ: 'Action' },
}) // '⌘ Action'

keyLabels wins over a layout entry, which wins over the fallback label. Layout entries get normal letter casing and key symbols, and missing or empty entries fall back. All of these options affect display only. keyLabels works anywhere, including on the server.

Format labels in server-rendered apps#

The server doesn't know the user's platform. Without one, a label rendered on the server uses 'linux', so a Mac user gets Ctrl+S in the server's HTML and ⌘ S once Svelte hydrates. To render the right label from the start:

1. Read the request's User-Agent header on the server, and pass detectPlatform(userAgent) as the provider's platform.
2. Format labels with getFormatForDisplay(). It reads the provider, so it uses the platform from step 1.

<script lang="ts">
  import { HotkeysProvider, detectPlatform } from '@tanstack/svelte-hotkeys'
  import Editor from './Editor.svelte'
</script>

<HotkeysProvider defaultOptions={{ platform: detectPlatform(userAgent) }}>
  <Editor />
</HotkeysProvider>

<script lang="ts">
  import { getFormatForDisplay } from '@tanstack/svelte-hotkeys'

  // Call it during component initialization, like getContext
  const formatForDisplay = getFormatForDisplay()
</script>

<ul>
  {#each commands as command (command.id)}
    <li>{command.name} <kbd>{formatForDisplay(command.hotkey)}</kbd></li>
  {/each}
</ul>

Call getFormatForDisplay once at the top level of the component's <script>, then call the function anywhere, including in markup, {#each} blocks, and $derived. The function reads the provider's platform each time you call it, so labels update when the platform changes. A platform passed to the function wins over the provider's.

In the browser, detectPlatform() reads the browser's own navigator, so the server and the browser get the same platform for practically every user. The provider's platform is also the default platform for hotkeys and recorders inside it. The provider that holds appHotkeys also compares app hotkeys on its platform, such as for conflicts. An inner provider, or a component that calls setHotkeysContext, inherits it.

Svelte has no fallback for a missing platform. Without a provider platform, getFormatForDisplay renders 'linux' labels on the server and the browser's platform during hydration. Svelte replaces the label during hydration without a warning, so Mac users see Ctrl+S until the page hydrates. Set the provider's platform on every page that renders on the server.

The provider must render on the server too, so wrap your app in it where the request is available, as shown for each framework below.

Pages rendered this way depend on the request's User-Agent header. If a CDN or another shared cache stores them, it can serve one user's labels, and the platform that Mod resolves to, to other users. Keep these pages out of shared caches, or add the platform to the cache key. Vary: User-Agent also works, but it splits the cache into many small entries.

SvelteKit#

Detect the platform in the root layout's server load function, and read it in the root layout. SvelteKit sends load data to the browser with the page:

// src/routes/+layout.server.ts
import { detectPlatform } from '@tanstack/svelte-hotkeys'
import type { LayoutServerLoad } from './$types'

export const load: LayoutServerLoad = ({ request }) => {
  const userAgent = request.headers.get('user-agent')
  // Prerendered pages have no request header, so the browser detects it
  return { platform: userAgent ? detectPlatform(userAgent) : undefined }
}

<!-- src/routes/+layout.svelte -->
<script lang="ts">
  import { HotkeysProvider } from '@tanstack/svelte-hotkeys'
  import type { LayoutProps } from './$types'

  let { data, children }: LayoutProps = $props()
</script>

<HotkeysProvider defaultOptions={{ platform: data.platform }}>
  {@render children()}
</HotkeysProvider>

A prerendered page gets no platform from this load function. Don't return detectPlatform() without a user agent: on the server it returns 'linux', and the browser would keep it, for labels and for Mod. For prerendered pages, see Static and prerendered pages.

The SvelteKit example shows this setup.

Astro#

Each Svelte island is mounted on its own, and context doesn't cross islands, so render the provider inside the island and pass the platform from the page. The page must render on demand to have a request: add export const prerender = false, or use output: 'server'.

---
// src/pages/index.astro
import { detectPlatform } from '@tanstack/svelte-hotkeys'
import Shortcuts from '../components/Shortcuts.svelte'

export const prerender = false
const platform = detectPlatform(Astro.request.headers.get('user-agent'))
---

<Shortcuts client:load platform={platform} />

<!-- src/components/Shortcuts.svelte -->
<script lang="ts">
  import { HotkeysProvider } from '@tanstack/svelte-hotkeys'
  import type { HotkeyPlatform } from '@tanstack/svelte-hotkeys'
  import CheatSheet from './CheatSheet.svelte'

  let { platform }: { platform: HotkeyPlatform } = $props()
</script>

<HotkeysProvider defaultOptions={{ platform }}>
  <CheatSheet />
</HotkeysProvider>

The Astro example shows this setup.

Render a label only in the browser#

To skip server rendering for a label instead, render it after the component mounts. Without a provider platform, the function from getFormatForDisplay detects the platform in the browser:

<script lang="ts">
  import { onMount } from 'svelte'
  import { getFormatForDisplay } from '@tanstack/svelte-hotkeys'

  const formatForDisplay = getFormatForDisplay()
  let mounted = $state(false)
  onMount(() => {
    mounted = true
  })
</script>

{#if mounted}
  <kbd>{formatForDisplay('Mod+S')}</kbd>
{:else}
  <kbd>&nbsp;</kbd>
{/if}

Framework options do the same for a whole page or island: export const ssr = false in a SvelteKit page or layout, or client:only="svelte" on an Astro island. A fallback with the label's width keeps the layout from shifting.

Static and prerendered pages#

A page rendered at build time has no request and no user, so getFormatForDisplay can't know the platform. This includes SvelteKit pages with export const prerender = true, sites built with adapter-static, and Astro's default static output. Without a provider platform, getFormatForDisplay shows 'linux' labels until the page hydrates, then switches. To show nothing until then, render the labels in a client-only wrapper, as above.

Development warning#

In development, formatting a label on the server without a platform logs a warning once. Without a platform, the server renders 'linux' labels, so users on macOS and Windows see a different label after hydration. If you develop on Linux, you won't see the problem yourself. The warning names the missing setting. It isn't included in production builds.

Format outside a component#

getFormatForDisplay reads the provider from context, so call it while a component initializes. Some code that builds labels isn't a component, such as a SvelteKit load function, a test, or a plain module. There, call the plain formatForDisplay function and pass the platform yourself:

import { formatForDisplay } from '@tanstack/svelte-hotkeys'

formatForDisplay('Mod+S', { platform }) // '⌘ S' when platform is 'mac'

The plain function takes the same options as the function from getFormatForDisplay. It doesn't read the provider, and it uses only the layoutMap you pass. Without a platform, it detects one in the browser and uses 'linux' on a server. To give it the user's layout, call loadKeyboardLayout() in the browser, and read the layout from getKeyboardLayoutStore().

The export is marked deprecated so that your editor points component code to getFormatForDisplay. Outside a component, it is the function to use.

Parse, compare, and store hotkeys#

parseHotkey returns each chord's key, as either a logical key or a physical code, plus its modifiers with Mod resolved. Check which one you have before reading it:

import { normalizeHotkey, parseHotkey } from '@tanstack/svelte-hotkeys'

const parsed = parseHotkey('Mod+[KeyS]', 'mac')
if (parsed.code !== undefined) {
  console.log(parsed.code) // 'KeyS'; parsed.key is undefined
}
const stored = normalizeHotkey(parsed, 'mac') // 'Mod+[KeyS]'

A parsed chord's modifiers are already resolved for one platform. To store it as a hotkey that works on every platform, normalize it with that same platform, as above. normalizeHotkey also accepts chord strings, chord objects, and sequences. Store hotkeys, never display labels. Write a chord as a string or an object covers the forms a hotkey can take.

areHotkeysEqual(a, b) compares chords or sequences after resolving modifiers, so Mod+S equals Meta+S on macOS. Sequences compare step by step. isHotkeySequence narrows a Hotkey to a sequence, and simplifyHotkey turns a one-step sequence into its chord.

Use validateHotkey when you accept a hotkey from somewhere else, such as a settings file. It returns valid, errors, and warnings. Each error or warning has a reason code, such as 'unknown-modifier', the part it's about, and for a sequence, the index of the step. The library sends no text, so write your own messages for users. The devtools describe each problem in the details of a hotkey. It can't promise that the browser or operating system delivers the shortcut. To check hotkeys as users record them, see Validate and check conflicts.

Try these options together with the format toggles in the server-rendered cheat sheet example. For a full list of your app's shortcuts, see Cheat Sheet UI Helpers.