JavaScript i18n: Browser-native Internationalisering met de Intl API
JavaScript bevat de Intl API als ingebouwde standaard voor het opmaken van getallen, datums, lijsten en het verwerken van meervoudsregels voor verschillende locales. Geen externe bibliotheken vereist. De API wordt ondersteund in alle moderne browsers en Node.js, met locale-bewuste tekenreeksvergelijking, segmentatie en relatieve tijdopmaak direct beschikbaar.
Add i18n to plain JavaScript in three steps
There is no JavaScript-specific package to install: @better-i18n/core is the plain-JavaScript client every other SDK here wraps.
Install the client
One dependency-free package. It runs in browsers, Node, Deno, Bun and Cloudflare Workers.
npm install @better-i18n/core
# Zero dependencies. Runs in browsers, Node, Deno,
# Bun and Cloudflare Workers.Create the client once
Instantiate at module scope so the 60-second in-memory cache is shared instead of rebuilt on every call.
import { createI18nCore } from '@better-i18n/core'
export const i18n = createI18nCore({
projectId: 'your-org/your-project', // Settings → General → Project ID
defaultLocale: 'en',
})Read a message
getMessages returns a plain nested object, so a four-line lookup helper is the whole runtime you need.
import { i18n } from './i18n.js'
const messages = await i18n.getMessages('en')
// getMessages resolves to { namespace: { key: value } }
const t = (path) =>
path.split('.').reduce((node, part) => node?.[part], messages) ?? path
document.querySelector('h1').textContent = t('home.title')
// Locales come from the project manifest, not a hardcoded array
const languages = await i18n.getLanguages()How it works
Where a JavaScript string comes from
No build step and no bundled locale files: the client resolves a locale at runtime and the edge answers it.
Read path — every locale load
Reads from the plain object getMessages() already returned.
0 network calls per render
getMessages(locale) — served from the in-memory cache if it is warm.
60s TTL · 0 deps
Cloudflare worker answers from the nearest edge cache.
max-age=60 · always 200
The published translation files the sync worker wrote.
source of truth
Fallback chain — tried in order when a hop fails
Write path — dashboard to app
Proposal reviewed in the dashboard, glossary enforced.
MCP · dashboard · CLI
Sync worker writes the locale files to R2.
better-i18n publish
Fire-and-forget purge of the affected keys and the manifest.
non-critical by design
The next getMessages() past the TTL returns the new copy.
~60s worst case
With the client, or with fetch
The client adds caching, retries and the fallback chain. If you would rather own that yourself, the CDN is a plain JSON endpoint.
import { i18n } from './i18n.js'
import { normalizeLocale } from '@better-i18n/core'
let current = 'en'
let messages = await i18n.getMessages(current)
export async function setLocale(next) {
// The CDN stores locales lowercased: pt-BR → pt-br
current = normalizeLocale(next)
messages = await i18n.getMessages(current)
document.documentElement.lang = current
render()
}JavaScript Intl API in de Praktijk
Formatteer valuta, datums en rangtelwoorden met behulp van ingebouwde Intl-constructors met landspecifieke uitvoer in elke moderne browser of Node.js-runtime.
// Using the built-in Intl API
const formatter = new Intl.NumberFormat('de-DE', {
style: 'currency',
currency: 'EUR',
});
console.log(formatter.format(1234.56)); // "1.234,56 €"
// Date formatting
const date = new Intl.DateTimeFormat('ja-JP', {
year: 'numeric',
month: 'long',
day: 'numeric',
});
console.log(date.format(new Date())); // "2026年3月2日"
// Pluralization
const plural = new Intl.PluralRules('en');
const suffixes = { one: 'st', two: 'nd', few: 'rd', other: 'th' };
function ordinal(n) {
return `${n}${suffixes[plural.select(n)]}`;
}JavaScript Intl API-functies
Gerelateerde Gidsen
Bekijk Andere Framework-gidsen
Get started
Begin Vandaag met JavaScript i18n
Beheer uw JavaScript-vertalingen met AI-gedreven workflows, CLI-synchronisatie en CDN-levering onder 50ms.