Migrate from Svelte I18n to Intlayer

Moving your Svelte application from svelte-i18n to Intlayer takes just a moment using the compat adapter.

What to do

Simply run the initialization command in your project:

npx intlayer init --interactive

This generates intlayer.config.ts. Ensure your SvelteKit / Vite plugins are wrapped with Intlayer's alias plugin to seamlessly map svelte-i18n to @intlayer/svelte-i18n.

What it does under the hood

Svelte-i18n relies on heavily used stores ($_, $t, $format, etc.) and ICU MessageFormat.

Under the hood:

• Stores: Intlayer proxies the svelte-i18n stores. $_ becomes a derived store of the current locale returning an Intlayer resolver.
• Keys: Your flat keys (e.g. $_('home.title')) are evaluated such that the first path segment represents the Intlayer dictionary.
• ICU Syntax: Fully handled by the shared ICU resolver (intl-messageformat equivalent parsing).
• Formatters: $date, $time, $number calls redirect safely to Intlayer's native core formatters.
• Babel/SWC Analysis: The Intlayer analyzer reads the Svelte store callers ($_) inside your .svelte source files before compilation to automatically build the relevant dictionary chunks.

To understand where these libraries come from, read the history of JavaScript i18n.