Introduction

Learn more about the DeepL API's capabilities and common use cases.

Get an API Key and Get Started

New user? Follow these quick steps to get started with the DeepL API.

Step 1: Sign up for the DeepL API at https://www.deepl.com/en/pro#developer

After logging in, you will find your API keys at https://www.deepl.com/en/your-account/keys

Step 2: Test your API key with a request.

Here are a few simple options that you can start with. Choose any one and replace{YOUR_API_KEY}with your own key.

Curl

Open a terminal.

Set the API key

export API_KEY={YOUR_API_KEY}

Sample request

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

Sample response

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

Python

Choose a local directory to work in.

Install client library

pip install deepl

Sample Request File

import deepl

auth_key = "{YOUR_API_KEY}"
translator = deepl.Translator(auth_key)

result = translator.translate_text("Hello, world!", target_lang="DE")
print(result.text)

Sample Response

Hallo, Welt!

NodeJS

Choose a local directory to work in.

Install client library

npm install deepl-node

Sample Request File

import * as deepl from 'deepl-node';

const authKey = "{YOUR_API_KEY}";
const translator = new deepl.Translator(authKey);

(async () => {
    const result = await translator.translateText('Hello, world!', null, 'de');
    console.log(result.text);
})();

Sample Response

Hallo, Welt!

Note: If you are on a free API account, you can replace https://api.deepl.com with https://api-free.deepl.com.

Step 3: Keep building with our client libraries and how-to guides.

You can use our API with popular programming languages (Python, JavaScript, .NET, PHP, Java, Ruby). Click here to learn more about our client libraries. You can also click here to find more examples and guides.

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About the DeepL API

For information about API updates and improvements, please refer to our release notes.

The DeepL API provides programmatic access to DeepL’s language AI technology, making it possible to bring high quality translation capabilities directly to your websites and applications.

Common use cases for the DeepL API:

• Website translation: Localize websites and expand to new markets efficiently and at scale—even in sectors like e-commerce and news media with a large catalog of dynamic content.

• Company communications: Integrate DeepL’s translation technology into your company’s systems such as Confluence and SharePoint. Enable your global teams to communicate seamlessly and with maximum data security.

• Building multilingual products: Translate chat conversations to connect users across language barriers in real time. Localize comments and product reviews with the click of a button. Make translation one of your differentiating features—however you imagine it.

In addition, many leading computer-assisted translation (CAT) tool providers have integrated DeepL’s technology into their software. This lets translators benefit from DeepL’s high-quality neural translations within their favorite translation tool. If you would like to develop a DeepL plugin for your CAT tool, please contact us at here.

Why the DeepL API?

• High-quality text and document translations: DeepL consistently outperforms the competition in translation quality—and not only for text translation. The API also supports .docx, .pptx, .xlsx, .txt, PDF, and HTML files.

• Maximum data security: DeepL API Pro texts aren’t saved on persistent storage and aren’t used to train our models. And DeepL adheres strictly to EU data protection laws and ISO 27001. Learn more about data security at DeepL.

• Customization with glossaries: Specify your own translations for words and phrases, and customize your translations consistently and at scale.

You can access the DeepL API with either a DeepL API Free or DeepL API Pro plan.

With the DeepL API Free plan, you can translate up to 500,000 characters per month for free.

For more advanced use cases, the DeepL API Pro plan allows unlimited translation with usage-based pricing, maximum data security, and prioritized execution of translation requests.

The following documentation applies to both plans. Please note that the API domain is different for each DeepL API plan, so please make sure to use the correct domain.

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