How to translate Strapi v4 Admin Panel

To translate Strapi’s V4 admin panel frontend first make sure you are running Strapi server using:
strapi develop --watch-admin command or else you’ll need to run strapi build for every change.

I spent a good 30min until I found out this.

So, go to the file src/admin/app.js and add the translates that you need:

export default {
  config: {
    // others configs
    locales: [
      "pt-BR",
      "fr"
    ],
  },
};

But note that is not possible to remove the English en translation because is the Strapi Admin Panel fallback language.

Overwriting

To overwrite any existing translation add a translations key inside the config object with the translation key/value of the language. You can see all Strapi default translations here or inside your project’s node_modules @strapi/admin/admin/src/translations/[language-name].json.

Here is an example to translate the Strapi navbar title and subtitle:

export default {
  config: {
    // others configs
    locales: [
      "pt-BR",
      "fr"
    ],
    translations: {
      "pt-BR": {
        "app.components.LeftMenu.navbrand.title": "Painel Admin",
        "app.components.LeftMenu.navbrand.workplace": "mywebsite.com",
      },
      fr: {
        "app.components.LeftMenu.navbrand.title": "Panneau d'administration",
        "app.components.LeftMenu.navbrand.workplace": "mywebsite.com",
      },
    },
  },
};

Result

After following the previous steps you will see language select at your profile page /admin/me and the login page.

Language select at Login page:

Language select at Profile page: