Displaying Hotkeys in Your Angular UI

Format a hotkey as a label whenever it appears in a menu, button, tooltip, cheat sheet, or shortcut settings panel. injectFormatForDisplay 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. injectFormatForDisplay works wherever your labels render:

Format a hotkey#

Call injectFormatForDisplay in an injection context, such as a field initializer. It returns the function that formats a hotkey:

import { Component } from '@angular/core'
import { injectFormatForDisplay } from '@tanstack/angular-hotkeys'

@Component({
  selector: 'app-save-button',
  template: `
    <button>
      Save <kbd>{{ formatForDisplay('Mod+S') }}</kbd>
    </button>
  `,
})
export class SaveButtonComponent {
  readonly formatForDisplay = injectFormatForDisplay()
}

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

• The platform from the nearest provideHotkeys, 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.

Inject it once, then call the function anywhere in the component, including in templates and in computed. 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 injectFormatForDisplay follow the user's keyboard where the browser reports its layout:

import { Component } from '@angular/core'
import { injectFormatForDisplay } from '@tanstack/angular-hotkeys'

@Component({
  selector: 'app-move-up',
  // 'W' on QWERTY, 'Z' on AZERTY
  template: `<kbd>{{ formatForDisplay('[KeyW]') }}</kbd>`,
})
export class MoveUpComponent {
  readonly formatForDisplay = injectFormatForDisplay()
}

• The layout loads after the first label renders. 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.

injectKeyboardLayout() returns a signal of 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:

provideHotkeys({ defaultOptions: { keyboardLayout: false } })

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 Angular hydrates the component. 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 injectFormatForDisplay(). It reads the provider, so it uses the platform from step 1.

import { REQUEST, inject } from '@angular/core'
import { detectPlatform, provideHotkeys } from '@tanstack/angular-hotkeys'

provideHotkeys({
  defaultOptions: () => ({
    platform: detectPlatform(
      inject(REQUEST)?.headers.get('user-agent'),
    ),
  }),
})

import { Component } from '@angular/core'
import { injectFormatForDisplay } from '@tanstack/angular-hotkeys'

@Component({
  selector: 'app-toolbar',
  template: `
    <ul>
      @for (command of commands; track command.id) {
        <li>{{ command.name }} <kbd>{{ formatForDisplay(command.hotkey) }}</kbd></li>
      }
    </ul>
  `,
})
export class ToolbarComponent {
  // Call it in an injection context, such as a field initializer
  readonly formatForDisplay = injectFormatForDisplay()
}

Inject it once, then call the function anywhere, including in templates. The function reads the provider's platform each time it runs, so a template updates 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 inherits it.

Without a provider platform, injectFormatForDisplay renders 'linux' labels on the server. Mac users see Ctrl+S until Angular hydrates the component. Set the provider's platform to avoid that.

The provider must run on the server too, so provide 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.

Angular SSR#

The REQUEST token from @angular/core is the current request on the server and null in the browser. Without a user agent, detectPlatform reads the browser's navigator, so the same provider works on both sides. Add it to the application config that the browser and server configs share:

// src/app/app.config.ts
import { REQUEST, inject } from '@angular/core'
import type { ApplicationConfig } from '@angular/core'
import { provideClientHydration } from '@angular/platform-browser'
import { detectPlatform, provideHotkeys } from '@tanstack/angular-hotkeys'

export const appConfig: ApplicationConfig = {
  providers: [
    provideClientHydration(),
    provideHotkeys({
      defaultOptions: () => ({
        platform: detectPlatform(
          inject(REQUEST)?.headers.get('user-agent'),
        ),
      }),
    }),
  ],
}

REQUEST is also null when a route is prerendered. See Static and prerendered pages.

The Angular SSR example shows this setup.

Analog#

injectRequest() from @analogjs/router/tokens returns the server's request on the server and null in the browser. The request is a Node.js request, so read the header from headers:

// src/app/app.config.ts
import type { ApplicationConfig } from '@angular/core'
import { injectRequest } from '@analogjs/router/tokens'
import { detectPlatform, provideHotkeys } from '@tanstack/angular-hotkeys'

export const appConfig: ApplicationConfig = {
  providers: [
    // ...your other providers
    provideHotkeys({
      defaultOptions: () => ({
        platform: detectPlatform(injectRequest()?.headers['user-agent']),
      }),
    }),
  ],
}

The Analog example shows this setup.

Render a label only in the browser#

To skip server rendering for a label instead, render it in a @defer block. On the server, Angular renders only the block's @placeholder. Without a provider platform, the function from injectFormatForDisplay detects the platform in the browser:

import { Component } from '@angular/core'
import { injectFormatForDisplay } from '@tanstack/angular-hotkeys'

@Component({
  selector: 'app-save-button',
  template: `
    <button (click)="save()">
      Save
      @defer (on immediate) {
        <kbd>{{ formatForDisplay('Mod+S') }}</kbd>
      } @placeholder {
        <kbd>&nbsp;</kbd>
      }
    </button>
  `,
})
export class SaveButtonComponent {
  readonly formatForDisplay = injectFormatForDisplay()

  save() {
    // ...
  }
}

To set a label from code instead, store it in a signal and set it in afterNextRender, which runs only in the browser. Don't switch templates with isPlatformBrowser: the server and the browser then render different content, which breaks hydration. A placeholder 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 injectFormatForDisplay can't know the platform. This includes routes with RenderMode.Prerender in app.routes.server.ts, and Analog's prerendered routes. Without a provider platform, injectFormatForDisplay shows 'linux' labels until Angular hydrates the component, then switches. To show nothing until then, render the labels only in the browser, as above. To render labels for each user instead, set the route's render mode to RenderMode.Server.

Development warning#

In development, formatting a label on the server without a platform logs a warning once, because users on macOS and Windows would get a 'linux' label first. The warning names the missing setting. It isn't included in production builds.

Format outside an injection context#

injectFormatForDisplay calls inject, so it needs an injection context, such as a field initializer or a constructor. Some code that builds labels has none, such as code at the top level of a module, or a test without TestBed. There, call the plain formatForDisplay function and pass the platform yourself:

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

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

The plain function takes the same options as the function from injectFormatForDisplay. 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 injectFormatForDisplay. Outside an injection context, 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/angular-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.