Universal Login Internationalization

New Universal Login Experience localization

The New Universal Login Experience is localized to the following languages:

Language Code
Bosnian bs
Bulgarian bg
Croatian hr
Czech cs
Chinese (Simplified) zh-CN
Chinese (Traditional) zh-TW
Danish da
Dutch nl
English en
Estonian es
Finnish fi
French fr-FR
French (Canada) fr-CA
German de
Greek el
Hindi hi
Hungarian hu
Indonesian id
Italian it
Icelandic is
Latvian lv
Lithuanian lt
Japanese ja
Korean ko
Norwegian nb
Polish pl
Portuguese (Brazilian) pt-BR
Portuguese (Portugal) pt-PT
Romanian ro
Russian ru
Serbian sb
Slovak sk
Slovenian sl
Spanish es
Swedish sv
Thai th
Vietnamese vi
Ukrainian uk
Turkish tr

Language selection

The language to render the pages will be selected based on:

  • The languages supported by Auth0, which are listed above.

  • The list of languages configured in Tenant Settings, where you can select the languages your tenant supports and select a default one. By default, the list has only English selected, but you can select the ones you need.

  • The value of the ui_locales parameter sent to the Authorization Request endpoint, which can be used to constrain the language list for an application or session. You can provide a space-delimited list of locales. The first locale on the list must match the enabled locale in your tenant to reflect in the UI.

  • The Accept-Language HTTP header sent by the browser. The pages will be rendered in this language if it is allowed by the settings above. If not, pages will be rendered in the default language.

Set tenant supported languages

You can set the supported and default languages in the Dashboard's Tenant Settings section.

You can also specify the enabled languages for the tenant via the Management API using the Update Tenant Settings endpoint. The first language in the list will be the default one.

curl --request PATCH \
  --url 'https://YOUR_DOMAIN/api/v2/tenants/settings' \
  --header 'authorization: Bearer API2_ACCESS_TOKEN' \
  --header 'content-type: application/json' \
  --data '{ "enabled_locales" : [ "en", "es"]}'
var client = new RestClient("https://YOUR_DOMAIN/api/v2/tenants/settings");
var request = new RestRequest(Method.PATCH);
request.AddHeader("content-type", "application/json");
request.AddHeader("authorization", "Bearer API2_ACCESS_TOKEN");
request.AddParameter("application/json", "{ \"enabled_locales\" : [ \"en\", \"es\"]}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
package main

import (

func main() {

	url := "https://YOUR_DOMAIN/api/v2/tenants/settings"

	payload := strings.NewReader("{ \"enabled_locales\" : [ \"en\", \"es\"]}")

	req, _ := http.NewRequest("PATCH", url, payload)

	req.Header.Add("content-type", "application/json")
	req.Header.Add("authorization", "Bearer API2_ACCESS_TOKEN")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := ioutil.ReadAll(res.Body)


HttpResponse<String> response = Unirest.patch("https://YOUR_DOMAIN/api/v2/tenants/settings")
  .header("content-type", "application/json")
  .header("authorization", "Bearer API2_ACCESS_TOKEN")
  .body("{ \"enabled_locales\" : [ \"en\", \"es\"]}")
var axios = require("axios").default;

var options = {
  method: 'PATCH',
  url: 'https://YOUR_DOMAIN/api/v2/tenants/settings',
  headers: {'content-type': 'application/json', authorization: 'Bearer API2_ACCESS_TOKEN'},
  data: {enabled_locales: ['en', 'es']}

axios.request(options).then(function (response) {
}).catch(function (error) {
#import <Foundation/Foundation.h>

NSDictionary *headers = @{ @"content-type": @"application/json",
                           @"authorization": @"Bearer API2_ACCESS_TOKEN" };
NSDictionary *parameters = @{ @"enabled_locales": @[ @"en", @"es" ] };

NSData *postData = [NSJSONSerialization dataWithJSONObject:parameters options:0 error:nil];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"https://YOUR_DOMAIN/api/v2/tenants/settings"]
[request setHTTPMethod:@"PATCH"];
[request setAllHTTPHeaderFields:headers];
[request setHTTPBody:postData];

NSURLSession *session = [NSURLSession sharedSession];
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request
                                            completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                                if (error) {
                                                    NSLog(@"%@", error);
                                                } else {
                                                    NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;
                                                    NSLog(@"%@", httpResponse);
[dataTask resume];
$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://YOUR_DOMAIN/api/v2/tenants/settings",
  CURLOPT_POSTFIELDS => "{ \"enabled_locales\" : [ \"en\", \"es\"]}",
    "authorization: Bearer API2_ACCESS_TOKEN",
    "content-type: application/json"

$response = curl_exec($curl);
$err = curl_error($curl);


if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
import http.client

conn = http.client.HTTPSConnection("")

payload = "{ \"enabled_locales\" : [ \"en\", \"es\"]}"

headers = {
    'content-type': "application/json",
    'authorization': "Bearer API2_ACCESS_TOKEN"

conn.request("PATCH", "/YOUR_DOMAIN/api/v2/tenants/settings", payload, headers)

res = conn.getresponse()
data = res.read()

require 'uri'
require 'net/http'
require 'openssl'

url = URI("https://YOUR_DOMAIN/api/v2/tenants/settings")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
http.verify_mode = OpenSSL::SSL::VERIFY_NONE

request = Net::HTTP::Patch.new(url)
request["content-type"] = 'application/json'
request["authorization"] = 'Bearer API2_ACCESS_TOKEN'
request.body = "{ \"enabled_locales\" : [ \"en\", \"es\"]}"

response = http.request(request)
puts response.read_body
import Foundation

let headers = [
  "content-type": "application/json",
  "authorization": "Bearer API2_ACCESS_TOKEN"
let parameters = ["enabled_locales": ["en", "es"]] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://YOUR_DOMAIN/api/v2/tenants/settings")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "PATCH"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
  } else {
    let httpResponse = response as? HTTPURLResponse



  • It is not possible to add additional languages.

  • The ui_locales parameter can only be used in OAuth flows, as it’s not available in SAML or WS-Federation.

  • The ui_locales parameter is not forwarded to upstream IdPs.

  • It is not possible to localize the scopes in the Consent page.

Classic Universal Login Experience localization

In the Classic Universal Login experience, localization is done using our JavaScript widgets for login, the password reset page and password policies.

The MFA page by default uses the Auth0 MFA Widget, which cannot be localized. You can create localized versions by using guardian.js.

It is not possible to localize the Consent page.

Learn more