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    Creation:2025-04-18Last update:2026-08-29

    Translate your Angular 22 (Vite) website using Intlayer | Internationalization (i18n)

    Table of Contents

    Why Intlayer over alternatives?

    Compared to main solutions like ngx-translate or angular-l10n, Intlayer is a solution that comes with integrated optimizations such as:

    Intlayer is optimized to work perfectly with Angular by offering component-level content scoping, lazy-loaded translations, and all the features needed for scaling internationalization (i18n).

    Instead of loading massive JSON files into your pages, load only the necessary content. Intlayer helps reduce your bundle and page sizes by up to 50%.

    Scoping your application's content facilitates maintenance for large-scale applications. You can duplicate or delete a single feature folder without the mental burden of reviewing your entire content codebase. Additionally, Intlayer is fully typed to ensure your content's accuracy.

    Co-locating content reduces the context needed by Large Language Models (LLMs). Intlayer also comes with a suite of tools, such as a CLI to test for missing translations,LSP, MCP, and agent skills, to make the developer experience (DX) even smoother for AI agents.

    Use automation to translate in your CI/CD pipeline using the LLM of your choice at the cost of your AI provider. Intlayer also offers a compiler to automate content extraction, as well as a web platform to help translate in the background.

    Connecting massive JSON files to components can lead to performance and reactivity issues. Intlayer optimizes your content loading at build time.

    More than just an i18n solution, Intlayer provides an self-hosted visual editor and a full CMS to help you manage your multilingual content in real-time, making collaboration with translators, copywriters, and other team members seamless. Content can be stored locally and/or remotely.


    Step-by-Step Guide to Set Up Intlayer in an Angular Application

    ide.intlayer.org
    intlayer-angular-22-template.vercel.app

    See Application Template on GitHub.

    1. Install Dependencies

      Install the necessary packages using npm:

      bash
      npx intlayer init --interactive
      
      the --interactive flag is optional. Use intlayer-cli init if you're an AI agent.
      This command will detect your environment and install the required packages. For example:
      bash
      npm install intlayer angular-intlayer
      npm install @angular-builders/custom-esbuild --save-dev
      
      • intlayer

        The core package that provides internationalization tools for configuration management, translation, content declaration, transpilation, and CLI commands.

      • angular-intlayer The package that integrates Intlayer with Angular application. It provides context providers and hooks for Angular internationalization.

      • @angular-builders/custom-esbuild Required to customize the esbuild configuration of Angular CLI.

    2. Configuration of your project

      Create a config file to configure the languages of your application:

      intlayer.config.ts
      import { Locales, type IntlayerConfig } from "intlayer";
      
      const config: IntlayerConfig = {
        internationalization: {
          locales: [
            Locales.ENGLISH,
            Locales.FRENCH,
            Locales.SPANISH,
            // Your other locales
          ],
          defaultLocale: Locales.ENGLISH,
        },
      };
      
      export default config;
      
      Through this configuration file, you can set up localized URLs, middleware redirection, cookie names, the location and extension of your content declarations, disable Intlayer logs in the console, and more. For a complete list of available parameters, refer to the configuration documentation.
    3. Integrate Intlayer in Your Angular Configuration

      To integrate Intlayer with the Angular CLI, you need to use a custom builder. This guide assumes you are using Vite/esbuild (default for Angular 22 projects).

      First, modify your angular.json to use the custom esbuild builder. Update the build and serve configurations:

      angular.json
      {
        "projects": {
          "your-app-name": {
            "architect": {
              "build": {
                "builder": "@angular-builders/custom-esbuild:application", // replace "@angular/build:application"
                "options": {
                  "define": {
                    "process.env": "{}",
                  },
                  "plugins": ["./esbuild.plugins.ts"],
                  "browser": "src/main.ts",
                  // ...
                },
              },
              "serve": {
                "builder": "@angular-builders/custom-esbuild:dev-server", // replace "@angular/build:dev-server"
                "options": {
                  "prebundle": {
                    "exclude": [
                      "intlayer",
                      "angular-intlayer",
                      "@intlayer/config/built",
                      "@intlayer/core"
                    ]
                },
              },
            },
          },
        },
      }
      
      Make sure to replace your-app-name with the actual name of your project in angular.json.

      Next, create a esbuild.plugins.ts file at the root of your project:

      esbuild.plugins.ts
      import { intlayerEsbuildPlugin } from "angular-intlayer/esbuild";
      
      export default [intlayerEsbuildPlugin()];
      
      The intlayerEsbuildPlugin function configures esbuild with Intlayer. It injects the plugin to handle content declaration files and sets up configurations for optimal performance.

      NX users: NX's Angular builders load plugin files via Node's native ESM resolution and do not compile TypeScript plugin files on the fly. Use a .mjs file instead and update the plugins reference in angular.json accordingly:

      esbuild.plugins.mjs
      import { intlayerEsbuildPlugin } from "angular-intlayer/esbuild";
      
      export default [intlayerEsbuildPlugin()];
      

      Then in angular.json point to "./esbuild.plugins.mjs" instead of "./esbuild.plugins.ts".

    4. Declare Your Content

      Create and manage your content declarations to store translations:

      Your content declarations can be defined anywhere in your application as soon they are included into the contentDir directory (by default, ./src). And match the content declaration file extension (by default, .content.{json,ts,tsx,js,jsx,mjs,cjs,md,mdx,yaml,yml}).
      For more details, refer to the content declaration documentation.
    5. Utilize Intlayer in Your Code

      To utilize Intlayer's internationalization features throughout your Angular application, you need to provide Intlayer in your application configuration.

      src/app/app.config.ts
      import { ApplicationConfig } from "@angular/core";
      import { provideRouter } from "@angular/router";
      import { provideIntlayer } from "angular-intlayer";
      import { routes } from "./app.routes";
      
      export const appConfig: ApplicationConfig = {
        providers: [
          provideRouter(routes),
          provideIntlayer(), // Add the Intlayer provider here
        ],
      };
      

      Then, you can use the useIntlayer function within any component.

      src/app/app.component.ts
      import { Component } from "@angular/core";
      import { RouterOutlet } from "@angular/router";
      import { useIntlayer } from "angular-intlayer";
      
      @Component({
        selector: "app-root",
        standalone: true,
        imports: [RouterOutlet],
        templateUrl: "./app.component.html",
        styleUrl: "./app.component.css",
      })
      export class AppComponent {
        content = useIntlayer("app");
      }
      

      And in your template:

      src/app/app.component.html
      <div class="content">
        <h1>{{ content().title }}</h1>
        <p>{{ content().congratulations }}</p>
      </div>
      

      Intlayer content is returned as a Signal, so you access the values by calling the signal: content().title.

    6. Change the language of your content

      Optional

      To change the language of your content, you can use the setLocale function provided by the useLocale function. This allows you to set the locale of the application and update the content accordingly.

      Create a component to switch between languages:

      src/app/locale-switcher.component.ts
      import { Component } from "@angular/core";
      import { CommonModule } from "@angular/common";
      import { useLocale } from "angular-intlayer";
      
      @Component({
        selector: "app-locale-switcher",
        standalone: true,
        imports: [CommonModule],
        template: `
          <div class="locale-switcher">
            <select
              [value]="locale()"
              (change)="setLocale($any($event.target).value)"
            >
              @for (loc of availableLocales; track loc) {
                <option [value]="loc">{{ loc }}</option>
              }
            </select>
          </div>
        `,
      })
      export class LocaleSwitcherComponent {
        localeCtx = useLocale();
      
        locale = this.localeCtx.locale;
        availableLocales = this.localeCtx.availableLocales;
        setLocale = this.localeCtx.setLocale;
      }
      

      Then, use this component in your app.component.ts:

      src/app/app.component.ts
      import { Component } from "@angular/core";
      import { RouterOutlet } from "@angular/router";
      import { useIntlayer } from "angular-intlayer";
      import { LocaleSwitcherComponent } from "./locale-switcher.component";
      
      @Component({
        selector: "app-root",
        standalone: true,
        imports: [RouterOutlet, LocaleSwitcherComponent],
        templateUrl: "./app.component.html",
        styleUrl: "./app.component.css",
      })
      export class AppComponent {
        content = useIntlayer("app");
      }
      

    Configure TypeScript

    Intlayer uses module augmentation to get benefits of TypeScript and make your codebase stronger.

    Autocompletion

    Translation error

    Ensure your TypeScript configuration includes the autogenerated types.

    tsconfig.json
    {
      // ... Your existing TypeScript configurations
      "include": [
        // ... Your existing TypeScript configurations
        ".intlayer/**/*.ts", // Include the auto-generated types
      ],
    }
    

    Git Configuration

    It is recommended to ignore the files generated by Intlayer. This allows you to avoid committing them to your Git repository.

    To do this, you can add the following instructions to your .gitignore file:

    bash
    # Ignore the files generated by Intlayer
    .intlayer
    

    VS Code Extension

    To improve your development experience with Intlayer, you can install the official Intlayer VS Code Extension.

    Install from the VS Code Marketplace

    This extension provides:

    • Autocompletion for translation keys.
    • Real-time error detection for missing translations.
    • Inline previews of translated content.
    • Quick actions to easily create and update translations.

    For more details on how to use the extension, refer to the Intlayer VS Code Extension documentation.


    Go Further

    To go further, you can implement the visual editor or externalize your content using the CMS.


    Frequently Asked Questions

    • @angular/localize, the built-in i18n: messages are extracted to XLIFF and each locale is compiled into its own build, which means one deployment artifact per language and no runtime locale switching.
    • ngx-translate and Transloco: runtime JSON catalogs loaded through a service, with locale switching but no build time typing.
    • Intlayer: the most advanced solution. Content declared anywhere in your codebase (next to each component or centralized) and compiled at build time, fully typed, with runtime locale switching, AI translation, a visual editor and a CMS.

    The usual reason to leave @angular/localize is the one build per locale model. Intlayer keeps a single build and switches language at runtime. See why Intlayer.

    Much less than a namespace based setup, because a page never downloads a catalog it does not render. The build time compiler replaces useIntlayer calls with the exact dictionary entries a component uses, so unused keys and unused languages are dropped, and dynamic dictionaries split the rest per locale. Measured against the usual alternatives, Intlayer reduces bundle and page size by up to 50%. See bundle optimization and the benchmark.

    Largely. Follow the ngx-translate migration guide or the Transloco migration guide to move the content over. You can also migrate gradually: the sync JSON plugin keeps your existing JSON catalogs as the source of truth and generates Intlayer dictionaries from them, so both layers stay in sync while you move templates across one at a time.

    Yes. The sync JSON plugin keeps your /messages/{locale}/{namespace}.json files as the source of truth and generates Intlayer dictionaries from them, in both directions. A sync PO plugin does the same for gettext catalogs, and per locale files let you split content by language instead of grouping locales in one file.

    No. Run npx intlayer extract and Intlayer reads your source files, pulls the user facing strings out and writes a .content file next to each one, so you review a diff instead of copying strings into a catalog one at a time. See the extract command.

    For a fully automated pipeline, the Intlayer Compiler does the same at build time on JSX, TSX, Vue and Svelte source, generating the dictionaries on every change so there are no keys to maintain by hand. It works by static analysis, so strings that only exist at runtime stay out of reach, and it needs a few annotations to tell user facing text apart from application logic.

    Five pieces, all optional:

    • VS Code extension: jump from a useIntlayer key to the content file that declares it, extract content from a component, and run build, fill, test, push and pull from the command palette or a dedicated Intlayer tab.
    • LSP server: the same awareness in any editor that speaks LSP, with go to definition, find all references, hover previews of a translated value, autocompletion of keys and fields, and a warning when a key is not declared anywhere. It also resolves i18next, react-i18next, next-intl and use-intl calls, which helps while you migrate.
    • MCP server: exposes the Intlayer documentation and CLI to Cursor, VS Code, Claude Desktop, Claude Code and ChatGPT, so an assistant answers from current docs instead of guessing, and can run commands such as intlayer fill itself.
    • Agent skills: focused skills such as intlayer-config, intlayer-cli and intlayer-content, plus one per framework, that teach an agent your routing setup and the content node types.
    • ESLint plugin: no-raw-text flags hardcoded strings, with further rules for static dictionary keys and unused content.