Your first API request

Make your first API requests to translate and improve text with the DeepL API.

Once you’ve created a DeepL API account and located your authentication key, you’re ready to make your first requests.

Text translation

To translate text, you can use the /translate endpoint, which also supports translation of XML and HTML content.

We included text translation examples for our client libraries, too, just to give you an idea of what they look like.

HTTP Request

If you chose a free API plan, replace https://api.deepl.com with https://api-free.deepl.com.

Example request

POST /v2/translate HTTP/2
Host: api.deepl.com
Authorization: DeepL-Auth-Key [yourAuthKey] 
User-Agent: YourApp/1.2.3
Content-Length: 45
Content-Type: application/json

{"text":["Hello, world!"],"target_lang":"DE"}

Example response

{
  "translations": [
    {
      "detected_source_language": "EN",
      "text": "Hallo, Welt!"
    }
  ]
}

cURL

If you chose a free API plan, replace https://api.deepl.com with https://api-free.deepl.com.

Example request

curl -X POST 'https://api.deepl.com/v2/translate' \
--header 'Authorization: DeepL-Auth-Key [yourAuthKey]' \
--header 'Content-Type: application/json' \
--data '{
  "text": [
    "Hello, world!"
  ],
  "target_lang": "DE"
}'

Example response

{
  "translations": [
    {
      "detected_source_language": "EN",
      "text": "Hallo, Welt!"
    }
  ]
}

Python

import deepl

auth_key = "f63c02c5-f056-..."  # replace with your key
deepl_client = deepl.DeepLClient(auth_key)

result = deepl_client.translate_text("Hello, world!", target_lang="FR")
print(result.text)  # "Bonjour à tous !"

In production code, it’s safer to store your API key in an environment variable.

JavaScript

import * as deepl from 'deepl-node';

const authKey = "f63c02c5-f056-..."; // Replace with your key
const deeplClient = new deepl.DeepLClient(authKey);

(async () => {
    const result = await deeplClient.translateText('Hello, world!', null, 'fr');
    console.log(result.text); // Bonjour à tous !
})();

In production code, it’s safer to store your API key in an environment variable.

PHP

require_once 'vendor/autoload.php';
use DeepL\Translator;

$authKey = "f63c02c5-f056-..."; // Replace with your key
$deeplClient = new \DeepL\DeepLClient($authKey);

$result = $deeplClient->translateText('Hello, world!', null, 'fr');
echo $result->text; // Bonjour, le monde!

In production code, it’s safer to store your API key in an environment variable.

C#

using DeepL; // this imports the DeepL namespace. Use the code below in your main program.

var authKey = "f63c02c5-f056-..."; // replace with your key
var client = new DeepLClient(authKey);

var translatedText = await client.TranslateTextAsync(
    "Hello, world!",
    null,
    LanguageCode.French);
Console.WriteLine(translatedText); // "Bonjour à tous !"

In production code, it’s safer to store your API key in an environment variable.

Java

import com.deepl.api.*;

public class Main {
    public static void main(String[] args) throws DeepLException, InterruptedException {
        String authKey = "{YOUR_API_KEY}"; // replace with your key
        DeepLClient client = new DeepLClient(authKey);

        TextResult result = client.translateText("Hello, world!", null, "fr");
        System.out.println(result.getText()); // "Bonjour à tous !"
    }
}

In production code, it’s safer to store your API key in an environment variable.

Ruby

require 'deepl'

DeepL.configure do |config|
    config.auth_key = '{YOUR_API_KEY}' # replace with your key
end

translation = DeepL.translate 'Hello, world!', nil, 'fr'
puts translation.text // "Bonjour à tous !"

In production code, it’s safer to store your API key in an environment variable.

Text improvement

To improve text, you can use the /write/rephrase endpoint. We included an example below.

The text improvement endpoint (DeepL API for Write) is currently only available to Pro API subscribers via the v2 endpoint.

Write API example: cURL

Example cURL request

curl -X POST 'https://api.deepl.com/v2/write/rephrase' \
--header 'Authorization: DeepL-Auth-Key [yourAuthKey]' \
--header 'Content-Type: application/json' \
--data '{
  "text": [
    "Its never to late too fix you'\''re grammer & speling!"
  ],
  "target_lang": "en-GB"
}'

Example response

{
  "improvements": [
    {
      "text": "It's never too late to fix your grammar and spelling!",
      "detected_source_language": "en",
      "target_language": "en-GB"
    }
  ]
}