Translating text (Advanced)

Cloud Translation - Advanced supports translating text by using custom models, and for creating glossaries to ensure that the Cloud Translation API translates a customer's domain-specific terminology correctly.

For instructions on installing the Google Cloud CLI, setting up a project with a service account, and obtaining an access token, see the Setup page. If you plan to use a glossary or the batch features, you also need to create a Cloud Storage bucket and grant your service account access to it.

To translate formatted documents, such as PDFs, see Translate documents.

Before you begin

Before you can start using the Cloud Translation API, you must have a project that has the Cloud Translation API enabled, and you must have the appropriate credentials. You can also install client libraries for common programming languages to help you make calls to the API. For more information, see the Setup page.

Comparing models

When you request translation from Cloud Translation - Advanced, you can specify which translation model to use. If no model is specified, the nmt model is used.

Model Best fit Examples
Neural Machine Translation (NMT) model

General text use cases such as common website content that is not specific to a domain, for example. news articles.

News articles, Social media, Chat applications, Reviews
AutoML Translation model Domain specific text. Customers provide training data specific to their use cases, for given language pairs to customize Google's NMT model for the domain purpose. Financial News, technical documents, any text that uses terms and jargon unique to that field.

You specify the translation model using its model ID. For the NMT model, the model ID is general/nmt. See the next section for information about AutoML Translation model IDs.

Translating text

The input text can be plain text or HTML. Cloud Translation API does not translate any HTML tags in the input, only text that appears between the tags. The output retains the (untranslated) HTML tags, with the translated text between the tags to the extent possible due to differences between the source and target languages. The order of HTML tags in the output may differ from the order in the input text due to word order changes in the translation.

Translating input strings

REST

To translate text, make a POST request and provide JSON in the request body that identifies the language to translate from (source_language_code), the language to translate to (target_language_code), and the text to translate (contents). You can provide multiple strings of text to translate by including them in your JSON (see example). You identify your source and target languages by using their ISO-639 codes.

The following shows an example of a POST request using curl or PowerShell. The example uses the access token for a service account set up for the project using the Google Cloud Google Cloud CLI. For instructions on installing the Google Cloud CLI, setting up a project with a service account, and obtaining an access token, see the Setup page.

Before using any of the request data, make the following replacements:

  • PROJECT_NUMBER_OR_ID: your Google Cloud project number or ID

HTTP method and URL: 

POST https://translation.googleapis.com/v3/projects/PROJECT_NUMBER_OR_ID:translateText

Request JSON body: 

{
  "sourceLanguageCode": "en",
  "targetLanguageCode": "ru",
  "contents": ["Dr. Watson, come here!", "Bring me some coffee!"]
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

{
  "translations": [
    {
      "translatedText": "Доктор Ватсон, иди сюда!",
    },
    {
      "translatedText": "Принеси мне кофе!",
    }
  ]
}

The translations array contains two translatedText fields with translations provided in the requested targetLanguageCode language (ru: Russian). The translations are listed in the same order as the corresponding source array in the request.

Go

Before trying this sample, follow the Go setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Go API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

// Imports the Google Cloud Translation library
import (
	"context"
	"fmt"
	"io"

	translate "cloud.google.com/go/translate/apiv3"
	"cloud.google.com/go/translate/apiv3/translatepb"
)


func translateText(w io.Writer, projectID string, sourceLang string, targetLang string, text string) error {
	// projectID := "my-project-id"
	// sourceLang := "en-US"
	// targetLang := "fr"
	// text := "Text you wish to translate"

	// Instantiates a client
	ctx := context.Background()
	client, err := translate.NewTranslationClient(ctx)
	if err != nil {
		return fmt.Errorf("NewTranslationClient: %w", err)
	}
	defer client.Close()

	// Construct request
	req := &translatepb.TranslateTextRequest{
		Parent:             fmt.Sprintf("projects/%s/locations/global", projectID),
		SourceLanguageCode: sourceLang,
		TargetLanguageCode: targetLang,
		MimeType:           "text/plain", // Mime types: "text/plain", "text/html"
		Contents:           []string{text},
	}

	resp, err := client.TranslateText(ctx, req)
	if err != nil {
		return fmt.Errorf("TranslateText: %w", err)
	}

	// Display the translation for each input text provided
	for _, translation := range resp.GetTranslations() {
		fmt.Fprintf(w, "Translated text: %v\n", translation.GetTranslatedText())
	}

	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Java API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

// Imports the Google Cloud Translation library.
import com.google.cloud.translate.v3.LocationName;
import com.google.cloud.translate.v3.TranslateTextRequest;
import com.google.cloud.translate.v3.TranslateTextResponse;
import com.google.cloud.translate.v3.Translation;
import com.google.cloud.translate.v3.TranslationServiceClient;
import java.io.IOException;


public class TranslateText {

  // Set and pass variables to overloaded translateText() method for translation.
  public static void translateText() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "YOUR-PROJECT-ID";
    // Supported Languages: https://cloud.google.com/translate/docs/languages
    String targetLanguage = "your-target-language";
    String text = "your-text";
    translateText(projectId, targetLanguage, text);
  }

  // Translate text to target language.
  public static void translateText(String projectId, String targetLanguage, String text)
      throws IOException {

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (TranslationServiceClient client = TranslationServiceClient.create()) {
      // Supported Locations: `global`, [glossary location], or [model location]
      // Glossaries must be hosted in `us-central1`
      // Custom Models must use the same location as your model. (us-central1)
      LocationName parent = LocationName.of(projectId, "global");

      // Supported Mime Types: https://cloud.google.com/translate/docs/supported-formats
      TranslateTextRequest request =
          TranslateTextRequest.newBuilder()
              .setParent(parent.toString())
              .setMimeType("text/plain")
              .setTargetLanguageCode(targetLanguage)
              .addContents(text)
              .build();

      TranslateTextResponse response = client.translateText(request);

      // Display the translation for each input text provided
      for (Translation translation : response.getTranslationsList()) {
        System.out.printf("Translated text: %s\n", translation.getTranslatedText());
      }
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Node.js API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const projectId = 'YOUR_PROJECT_ID';
// const location = 'global';
// const text = 'text to translate';

// Imports the Google Cloud Translation library
const {TranslationServiceClient} = require('@google-cloud/translate');

// Instantiates a client
const translationClient = new TranslationServiceClient();

async function translateText() {
  // Construct request
  const request = {
    parent: `projects/${projectId}/locations/${location}`,
    contents: [text],
    mimeType: 'text/plain', // mime types: text/plain, text/html
    sourceLanguageCode: 'en',
    targetLanguageCode: 'sr-Latn',
  };

  // Run request
  const [response] = await translationClient.translateText(request);

  for (const translation of response.translations) {
    console.log(`Translation: ${translation.translatedText}`);
  }
}

translateText();

Python

Before trying this sample, follow the Python setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Python API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

# Imports the Google Cloud Translation library
from google.cloud import translate


# Initialize Translation client
def translate_text(
        text: str = "YOUR_TEXT_TO_TRANSLATE",
        project_id: str = "YOUR_PROJECT_ID"
) -> translate.TranslationServiceClient:
    """Translating Text."""

    client = translate.TranslationServiceClient()

    location = "global"

    parent = f"projects/{project_id}/locations/{location}"

    # Translate text from English to French
    # Detail on supported types can be found here:
    # https://cloud.google.com/translate/docs/supported-formats
    response = client.translate_text(
        request={
            "parent": parent,
            "contents": [text],
            "mime_type": "text/plain",  # mime types: text/plain, text/html
            "source_language_code": "en-US",
            "target_language_code": "fr",
        }
    )

    # Display the translation for each input text provided
    for translation in response.translations:
        print(f"Translated text: {translation.translated_text}")

    return response

Additional languages

C#: Please follow the C# setup instructions on the client libraries page and then visit the Cloud Translation reference documentation for .NET.

PHP: Please follow the PHP setup instructions on the client libraries page and then visit the Cloud Translation reference documentation for PHP.

Ruby: Please follow the Ruby setup instructions on the client libraries page and then visit the Cloud Translation reference documentation for Ruby.

Translating text using a custom model

REST

You can specify which model to use for translation by using the model query parameter.

The following example translates text by using a custom model with a model ID of 1395675701985363739. You can get the model ID for a custom model from the list of models in the Google Cloud console or from the API response when you train the model.

Before using any of the request data, make the following replacements:

  • PROJECT_ID: Your Google Cloud project ID.
  • LOCATION: The region where the custom model is located, such as us-central1.

HTTP method and URL: 

POST https://translation.googleapis.com/v3/projects/PROJECT_ID/locations/LOCATION:translateText

Request JSON body: 

{
  "model": "projects/PROJECT_ID/locations/LOCATION/models/1395675701985363739",
  "sourceLanguageCode": "en",
  "targetLanguageCode": "ru",
  "contents": ["Dr. Watson, please discard your trash. You've shared unsolicited email with me.
  Let's talk about spam and importance ranking in a confidential mode."]
}

To send your request, choose one of these options:

curl

Save the request body in a file named request.json, and execute the following command: 

curl -X POST \
    -H "Authorization: Bearer $(gcloud auth application-default print-access-token)" \
    -H "Content-Type: application/json; charset=utf-8" \
    -d @request.json \
    "https://translation.googleapis.com/v3/projects/PROJECT_ID/locations/LOCATION:translateText"

PowerShell

Save the request body in a file named request.json, and execute the following command: 

$cred = gcloud auth application-default print-access-token
$headers = @{ "Authorization" = "Bearer $cred" }

Invoke-WebRequest `
    -Method POST `
    -Headers $headers `
    -ContentType: "application/json; charset=utf-8" `
    -InFile request.json `
    -Uri "https://translation.googleapis.com/v3/projects/PROJECT_ID/locations/LOCATION:translateText" | Select-Object -Expand Content

You should receive a JSON response similar to the following:

{
  "translation": {
    "translatedText": "Доктор Ватсон, пожалуйста, откажитесь от своего мусора.
    Вы поделились нежелательной электронной почтой со мной. Давайте поговорим о
    спаме и важности рейтинга в конфиденциальном режиме.",
    "model": "projects/PROJECT_NUMBER/locations/LOCATION/models/1395675701985363739"
  }
}

Go

Before trying this sample, follow the Go setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Go API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

import (
	"context"
	"fmt"
	"io"

	translate "cloud.google.com/go/translate/apiv3"
	"cloud.google.com/go/translate/apiv3/translatepb"
)

// translateTextWithModel translates input text and returns translated text.
func translateTextWithModel(w io.Writer, projectID string, location string, sourceLang string, targetLang string, text string, modelID string) error {
	// projectID := "my-project-id"
	// location := "us-central1"
	// sourceLang := "en"
	// targetLang := "fr"
	// text := "Hello, world!"
	// modelID := "your-model-id"

	ctx := context.Background()
	client, err := translate.NewTranslationClient(ctx)
	if err != nil {
		return fmt.Errorf("NewTranslationClient: %w", err)
	}
	defer client.Close()

	req := &translatepb.TranslateTextRequest{
		Parent:             fmt.Sprintf("projects/%s/locations/%s", projectID, location),
		SourceLanguageCode: sourceLang,
		TargetLanguageCode: targetLang,
		MimeType:           "text/plain", // Mime types: "text/plain", "text/html"
		Contents:           []string{text},
		Model:              fmt.Sprintf("projects/%s/locations/%s/models/%s", projectID, location, modelID),
	}

	resp, err := client.TranslateText(ctx, req)
	if err != nil {
		return fmt.Errorf("TranslateText: %w", err)
	}

	// Display the translation for each input text provided
	for _, translation := range resp.GetTranslations() {
		fmt.Fprintf(w, "Translated text: %v\n", translation.GetTranslatedText())
	}

	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Java API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

import com.google.cloud.translate.v3.LocationName;
import com.google.cloud.translate.v3.TranslateTextRequest;
import com.google.cloud.translate.v3.TranslateTextResponse;
import com.google.cloud.translate.v3.Translation;
import com.google.cloud.translate.v3.TranslationServiceClient;
import java.io.IOException;

public class TranslateTextWithModel {

  public static void translateTextWithModel() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "YOUR-PROJECT-ID";
    // Supported Languages: https://cloud.google.com/translate/docs/languages
    String sourceLanguage = "your-source-language";
    String targetLanguage = "your-target-language";
    String text = "your-text";
    String modelId = "YOUR-MODEL-ID";
    translateTextWithModel(projectId, sourceLanguage, targetLanguage, text, modelId);
  }

  // Translating Text with Model
  public static void translateTextWithModel(
      String projectId, String sourceLanguage, String targetLanguage, String text, String modelId)
      throws IOException {

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (TranslationServiceClient client = TranslationServiceClient.create()) {
      // Supported Locations: `global`, [glossary location], or [model location]
      // Glossaries must be hosted in `us-central1`
      // Custom Models must use the same location as your model. (us-central1)
      String location = "us-central1";
      LocationName parent = LocationName.of(projectId, location);
      String modelPath =
          String.format("projects/%s/locations/%s/models/%s", projectId, location, modelId);

      // Supported Mime Types: https://cloud.google.com/translate/docs/supported-formats
      TranslateTextRequest request =
          TranslateTextRequest.newBuilder()
              .setParent(parent.toString())
              .setMimeType("text/plain")
              .setSourceLanguageCode(sourceLanguage)
              .setTargetLanguageCode(targetLanguage)
              .addContents(text)
              .setModel(modelPath)
              .build();

      TranslateTextResponse response = client.translateText(request);

      // Display the translation for each input text provided
      for (Translation translation : response.getTranslationsList()) {
        System.out.printf("Translated text: %s\n", translation.getTranslatedText());
      }
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Node.js API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const projectId = 'YOUR_PROJECT_ID';
// const location = 'us-central1';
// const modelId = 'YOUR_MODEL_ID';
// const text = 'text to translate';

// Imports the Google Cloud Translation library
const {TranslationServiceClient} = require('@google-cloud/translate');

// Instantiates a client
const translationClient = new TranslationServiceClient();
async function translateTextWithModel() {
  // Construct request
  const request = {
    parent: `projects/${projectId}/locations/${location}`,
    contents: [text],
    mimeType: 'text/plain', // mime types: text/plain, text/html
    sourceLanguageCode: 'en',
    targetLanguageCode: 'ja',
    model: `projects/${projectId}/locations/${location}/models/${modelId}`,
  };

  // Run request
  const [response] = await translationClient.translateText(request);

  for (const translation of response.translations) {
    console.log(`Translated Content: ${translation.translatedText}`);
  }
}

translateTextWithModel();

Python

Before trying this sample, follow the Python setup instructions in the Cloud Translation quickstart using client libraries. For more information, see the Cloud Translation Python API reference documentation.

To authenticate to Cloud Translation, set up Application Default Credentials. For more information, see Set up authentication for a local development environment. 


from google.cloud import translate


def translate_text_with_model(
    text: str = "YOUR_TEXT_TO_TRANSLATE",
    project_id: str = "YOUR_PROJECT_ID",
    model_id: str = "YOUR_MODEL_ID",
) -> translate.TranslationServiceClient:
    """Translates a given text using Translation custom model."""

    client = translate.TranslationServiceClient()

    location = "us-central1"
    parent = f"projects/{project_id}/locations/{location}"
    model_path = f"{parent}/models/{model_id}"

    # Supported language codes: https://cloud.google.com/translate/docs/languages
    response = client.translate_text(
        request={
            "contents": [text],
            "target_language_code": "ja",
            "model": model_path,
            "source_language_code": "en",
            "parent": parent,
            "mime_type": "text/plain",  # mime types: text/plain, text/html
        }
    )
    # Display the translation for each input text provided
    for translation in response.translations:
        print(f"Translated text: {translation.translated_text}")

    return response

Additional languages

C#: Please follow the C# setup instructions on the client libraries page and then visit the Cloud Translation reference documentation for .NET.

PHP: Please follow the PHP setup instructions on the client libraries page and then visit the Cloud Translation reference documentation for PHP.

Ruby: Please follow the Ruby setup instructions on the client libraries page and then visit the Cloud Translation reference documentation for Ruby.

Transliteration

Transliteration is a configuration setting in the translateText method. When you enable transliteration, you translate romanized text (Latin script) directly to a target language. For example, you can translate romanized Japanese text directly to English, Spanish, or Chinese. The resulting translations are in the target language's writing system.

In your transliteration requests, include only romanized text. If you mix romanized text with non-romanized text, Cloud Translation can't ensure consistent and proper translations.

Considerations

Transliteration differs from standard text translations in the following ways:

  • Transliteration supports a limited number of languages. For more information, see the Transliteration column on the Supported languages page.
  • The MIME type must be text/plain. HTML is not supported.
  • Transliteration is supported by the default standard model only. Custom models aren't supported.
  • Transliteration has a lower default content quota. For more information, see Quotas and limits.

REST

Set the transliteration_config field on the translateText method.

Before using any of the request data, make the following replacements:

  • PROJECT_NUMBER_OR_ID: Your Google Cloud project number or ID
  • LOCATION: Region where you want to run this operation. For example, us-central1.
  • SOURCE_LANGUAGE: (Optional) The language code of the input text. If known, set to one of the language codes listed in Language support.
  • TARGET_LANGUAGE: The target language to translate the input text to. Set to one of the language codes listed in Language support.
  • SOURCE_TEXT: Romanized text in the source language to translate.

HTTP method and URL: 

POST https://translation.googleapis.com/v3/projects/PROJECT_NUMBER_OR_ID/locations/LOCATION:translateText

Request JSON body: 

{
  "source_language_code": "SOURCE_LANGUAGE",
  "target_language_code": "TARGET_LANGUAGE",
  "contents": "SOURCE_TEXT",
  "mime_type": "text/plain",
  "transliteration_config": { "enable_transliteration": true}
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

{
  "translations": [
    {
      "translatedText": "TRANSLATED_TEXT",
    }
  ]
}

Additional resources

  • For help on resolving common issues or errors, see the Troubleshooting page.