Overview
DeepL is a commercial Language AI service for translating text and documents, improving writing, and handling speech workflows. Its web products support translation and writing assistance, while the developer platform exposes Translate, Document, Voice, and Write APIs. The APIs can process text, HTML, and common office files, with glossary and formality controls; document translation is designed to preserve layout. It is aimed at individuals, organizations, and developers integrating multilingual communication into websites and internal applications. DeepL publishes official client libraries, but the product itself is closed source.