Language release process

Here's what API users can expect when DeepL adds translation support for a new language or language variant..

On a regular basis, DeepL adds translation support for new languages or language variants. In this article, we describe the process we'll follow with a new language or variant release.

• We will add the language code for the newly supported language or variant to the “Source languages” and “Target languages” lists on the Supported languages page in the API documentation. We’ll include a note on that page if the language or variant does not support both text and document translation.

• If a newly added language or variant supports both text and document translation, we will add the language or variant to the /languages endpoint response. Note that for language variants, we do not use a single, consistent format for the variant code:

  • In some cases, a variant is primarily used in a specific region, and so a 2-letter region code is the best way to identify the variant. For English and Portuguese variants, we use a 2-letter region code (e.g. EN-US, PT-BR).

  • In other cases, a variant is used widely across multiple regions, and so a single 2-letter region code isn’t the best way to identify the variant. For simplified and traditional Chinese variants, we use a variant code that is not region-specific (e.g. ZH-HANS, ZH-HANT). The decision of what variant code to use will depend on the characteristics of the variant itself, and variant codes will be selected by DeepL on a case-by-case basis.

• In cases where a new language code with a variant duplicates the behavior of an existing language code without a variant (e.g. ZH-HANS was recently added as a language code for translating into simplified Chinese, along with ZH):

  • In the /languages endpoint response, we will continue to return both language codes in two separate dicts with the same value in the “name” field.

  • For backwards compatibility, we will continue to support the original language code (in this example, ZH) for text and document translation.

• We will add the language code for the newly supported language or variant to our OpenAPI spec.

Note about the /languages endpoint: In the future, we plan to extend the language information returned by the API.

This will allow us to specify whether a language supports both text and document translation, whether a language code is considered deprecated because it’s been duplicated by a variant language code, and so on.

The additional metadata would also allow us, for example, to add languages like AR and ZH-HANT to the languages endpoint even before document translation is supported.