Login Page Languages

AuthAction’s hosted pages — login, signup, password reset, email verification, consent, and passkey — are available in seven languages. No configuration is required; the language is chosen per authorization request.

Supported Languages

Language	Code
English	`en`
German	`de`
French	`fr`
Spanish	`es`
Portuguese	`pt`
Italian	`it`
Dutch	`nl`

English is the default. Portuguese uses Brazilian Portuguese.

Selecting a Language

Pass the standard OpenID Connect ui_locales parameter on the authorization request:

https://<tenant-name>.<region>.authaction.com/oauth2/authorize
  ?client_id=<your-client-id>
  &redirect_uri=<your-redirect-uri>
  &response_type=code
  &scope=openid%20profile%20email
  &ui_locales=de

The selected language is kept for the rest of the flow, so a user who starts in German stays in German through signup, password reset, and consent.

ui_locales accepts a space-separated list in order of preference. The first supported language wins:

ui_locales=da%20nl%20en

Danish is not supported, so this renders in Dutch.

Matching Rules

Region subtags are ignored. de-AT and de-CH both match de. This means regional variants of the same language cannot be served separately — pt-PT resolves to pt, which is Brazilian Portuguese.

Matching is case-insensitive. DE and de behave the same.

Unsupported or missing values fall back to English. An unrecognised language is not an error — the page renders in English.

Using It From an SDK

Most OIDC libraries let you pass additional authorization parameters. For example, with the AuthAction web SDK:

await client.loginWithRedirect({
  authorizationParams: {
    ui_locales: "fr",
  },
});

A common pattern is to forward the user’s browser preference:

await client.loginWithRedirect({
  authorizationParams: {
    ui_locales: navigator.language,
  },
});

Since region subtags are ignored, fr-CA from the browser correctly resolves to French.

To apply the same language to every request, set it once when creating the client:

const client = new AuthActionClient({
  domain: "myapp.eu.authaction.com",
  clientId: "your-client-id",
  redirectUri: "http://localhost:5173/callback",
  authorizationParams: {
    ui_locales: "fr",
  },
});

Parameters passed to loginWithRedirect() override those set on the client.

Applications: Configure redirect URIs and application settings.
OIDC Prompt Parameter: Other authorization request parameters.

Login Page Languages

Supported Languages

Selecting a Language

Matching Rules

Using It From an SDK

Related