Translate documents

The document translation API allows you to translate whole documents and supports the following file types and extensions:

  • docx / doc - Microsoft Word Document

  • pptx - Microsoft PowerPoint Document

  • xlsx - Microsoft Excel Document

  • pdf - Portable Document Format

  • htm / html - HTML Document

  • txt - Plain Text Document

  • xlf / xliff - XLIFF Document, version 2.1

  • srt - SRT (SubRip Subtitle) Document

Please note that with every submitted document of type .pptx, .docx, .doc, .xlsx, or .pdf, you are billed a minimum of 50,000 characters with the DeepL API plan, no matter how many characters are included in the document.

The maximum upload limit for documents is available here and may vary based on API plan and document type.

We also provide a spec that is auto-generated from DeepL's OpenAPI file. You can find it here.

When translating a doc file, you will receive a docx file as the output format.


Step 1: upload a document to the /document endpoint

This call uploads a document and queues it for translation. The call returns once the upload is complete, returning a document ID and key which can be used to query the translation status and to download the translated document once translation is complete.

Because the request includes a file upload, it must be an HTTP POST request with content type multipart/form-data.

Please be aware that the uploaded document is automatically removed from the server once the translated document has been downloaded. You have to upload the document again in order to restart the translation.

You may specify the glossary to use for the document translation using the glossary_id parameter. Important: This requires the source_lang parameter to be set and the language pair of the glossary has to match the language pair of the request.

For more detail about request body parameters, see the Request Body Descriptions section further down on the page.

The examples below use our API Pro endpoint https://api.deepl.com. If you're an API Free user, remember to update your requests to use https://api-free.deepl.com instead.

Example request: document upload (no glossary)
curl -X POST 'https://api.deepl.com/v2/document' \
--header 'Authorization: DeepL-Auth-Key [yourAuthKey]' \
--form 'target_lang=DE' \
--form 'file=@document.docx'
Example request: document upload (with glossary)
curl -X POST 'https://api.deepl.com/v2/document' \
--header 'Authorization: DeepL-Auth-Key [yourAuthKey]' \
--form 'source_lang=EN' \
--form 'target_lang=DE' \
--form 'file=@document.docx' \
--form 'glossary_id=[yourGlossaryId]' 
Example response
{
  "document_id": "04DE5AD98A02647D83285A36021911C6",
  "document_key": "0CB0054F1C132C1625B392EADDA41CB754A742822F6877173029A6C487E7F60A"
}

These examples are for demonstration purposes only. In production code, the authentication key should not be hard-coded but instead fetched from a configuration file or environment variable.

Request Body Descriptions

Body parameterDescription

source_lang (optional)

Language of the text to be translated. If omitted, the API will attempt to detect the language of the text and translate it. You can find supported languages here. Type: string

target_lang (required)

The language into which the text should be translated. You can find supported languages here. Type: string

file (required)

The document file to be translated. The file name should be included in this part's content disposition. As an alternative, the filename parameter can be used. The following file types and extensions are supported:

  • docx - Microsoft Word Document

  • pptx - Microsoft PowerPoint Document

  • xlsx - Microsoft Excel Document

  • pdf - Portable Document Format

  • htm / html - HTML Document

  • txt - Plain Text Document

  • xlf / xliff - XLIFF Document, version 2.1

Type: binary

filename (optional)

The name of the uploaded file. Can be used as an alternative to including the file name in the file part's content disposition. Type: string

formality (optional)

Sets whether the translated text should lean towards formal or informal language. This feature currently only works for target languages DE (German), FR (French), IT (Italian), ES (Spanish), NL (Dutch), PL (Polish), PT-BR and PT-PT (Portuguese), JA (Japanese), and RU (Russian). Learn more about the plain/polite feature for Japanese here. Setting this parameter with a target language that does not support formality will fail, unless one of the prefer_... options are used. Possible options are:

  • default (default)

  • more - for a more formal language

  • less - for a more informal language

  • prefer_more - for a more formal language if available, otherwise fallback to default formality

  • prefer_less - for a more informal language if available, otherwise fallback to default formality

Type: string

glossary_id (optional)

A unique ID assigned to a glossary. Type: string

output_format (optional)

File extension of desired format of translated file, for example: pdf. If unspecified, by default the translated file will be in the same format as the input file.

Note: Not all combinations of input file and translation file extensions are permitted. See Document format conversions for the permitted combinations.

Type: string

Step 2: check the document status and wait for translation to complete

Retrieve the current status of a document translation process.

Please note that the seconds_remaining parameter is just an estimate and can be unreliable (e.g. sometimes it might return 2^27). We recommend polling the document status, either in regular intervals or with exponential back-off. Translation time depends on the document size and server load, but should be in the order of seconds for small documents and 1-2 minutes for larger documents once translation has started.

The example below uses our API Pro endpoint https://api.deepl.com. If you're an API Free user, remember to update your requests to use https://api-free.deepl.com instead.

Example request: check document status
curl -X POST 'https://api.deepl.com/v2/document/{document_id}' \
--header 'Authorization: DeepL-Auth-Key [yourAuthKey]' \
--header 'Content-Type: application/json' \
--data '{
  "document_key": "0CB0054F1C132C1625B392EADDA41CB754A742822F6877173029A6C487E7F60A"
}'
Example response: translating
{
  "document_id": "04DE5AD98A02647D83285A36021911C6",
  "status": "translating",
  "seconds_remaining": 20
}
Example response: done
{
  "document_id": "04DE5AD98A02647D83285A36021911C6",
  "status": "done",
  "billed_characters": 1337
}
Example response: queued
{
  "document_id": "04DE5AD98A02647D83285A36021911C6",
  "status": "queued"
}
Example response: error
{
  "document_id": "04DE5AD98A02647D83285A36021911C6",
  "status": "error",
  "message": "Source and target language are equal."
}

Step 3: download the translated document

Once the status of the document translation process is done, the result can be downloaded.

For privacy reasons the translated document is automatically removed from the server once it was downloaded and cannot be downloaded again.

The example below uses our API Pro endpoint https://api.deepl.com. If you're an API Free user, remember to update your requests to use https://api-free.deepl.com instead.

Example request: download translated document
curl -X POST 'https://api.deepl.com/v2/document/{document_id}/result' \
--header 'Authorization: DeepL-Auth-Key [yourAuthKey]' \
--header 'Content-Type: application/json' \
--data '{
  "document_key": "0CB0054F1C132C1625B392EADDA41CB754A742822F6877173029A6C487E7F60A"
}'

Client libraries and document translation

The examples on this page show how to translate documents with DeepL using the API directly.

DeepL's client libraries simplify API document translation by providing a convenience function to upload the document, check translation status and download the translated document with a single function call.

Document format conversions

By default, the DeepL API returns translated documents in the same format as the input document.

Using the output_format parameter during document upload, you can select alternative output formats. For example, you can translate a PDF file and receive the translation as an editable Microsoft Word Document (DOCX), allowing you to make additional changes as necessary.

The range of alternative output formats you can select are indicated in the table below:

Input document formatAlternative output document formats

PDF

docx - Microsoft Word Document

Others

None

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