DeepL API

What it does

The DeepL API takes in text, HTML, documents (PDF, Word, PowerPoint and other formats) or live speech, and returns translated text, translated files that keep their original formatting, rewritten or corrected writing, or transcribed and translated audio. It is split into Translate, Document, Write and Voice APIs, called over HTTP or through official client libraries.

Teams embed it in their own websites, apps, e-commerce stores and contact-centre tools rather than using it as a standalone app. Glossaries, style rules and formality control keep output consistent and on-brand, and Write lets you set a style or tone. Voice offers streaming speech-to-text and speech-to-speech. DeepL says Pro customer data is never used to train its models, and lists ISO 27001, SOC 2 Type II, HIPAA and GDPR certifications.

It suits developers and technical teams adding multilingual or writing features to products and internal systems. You need an API key from a sign-up, and the free API uses a separate endpoint from the paid one. Limitations: usage-based rates were not confirmed, an existing DeepL Translator account cannot be reused for API sign-up, and language coverage varies by API.

What it can do

• Translate text and HTML via the Translate API in 100+ languages, with glossary and formality control
• Translate documents (PDF, DOCX, PPTX, HTML and more) while preserving formatting, up to 100 MB per document
• Rewrite, correct and restyle content with the Write API, including style and tone selection
• Real-time speech-to-text and speech-to-speech translation with the Voice API, with specialised vocabulary support
• Enforce consistent terminology and style with glossaries and style rules
• Manage API keys, permissions and usage via the account UI or the Admin API

Works with

• AWS Marketplace
• Official SDKs (Python, JavaScript, Java, .NET, Ruby, PHP)
• DeepL MCP Server

Example workflows

Localise a help-centre site

Input: HTML pages and PDF or Word guides. Steps: create a glossary of product terms, call the Translate and Document APIs per target language, review the output. Output: translated pages and files with formatting kept and consistent terminology.

Multilingual support calls

Input: live customer audio in one language. Steps: stream audio to the Voice API with specialised vocabulary, show on-screen transcription and translation to the agent. Output: translated audio and text during the call.

Before you choose

• Free and paid API plans use different endpoints (api-free.deepl.com vs api.deepl.com).
• Language coverage differs by API: Translate lists 100+ languages, Voice 40+.
• The API plans page was not included, so confirm rates and quotas on the official pricing page before committing.

Listed under

• Productivity
• Writing and docs
• API
• Developers
• Document translation
• Enterprise
• Glossaries
• Localization

Get started

Sign up, then copy the key from the console; free API key offered without a credit card.

1. Sign up for an API plan (free or paid) with a new account, since an existing Translator account must be logged out.
2. Copy your API key from the account and store it in an environment variable.
3. Install an official client library (for example pip install deepl) and send a first translate request, using api-free.deepl.com if on a free plan.

A free API key is offered with no credit card. Paid API plan rates and meters were not confirmed. The DeepL Pro page prices apply to the Translator app, not the API.

We couldn’t find published prices for DeepL API. See their pricing page ↗

Sources for this overview

Product pages, documentation, and pricing checked 29 Oct 2026. Each source supports part of the overview; availability and prices can change.

• The DeepL API for translation and writing improvement at scale ↗www.deepl.com
• Quickstart - DeepL Documentation ↗developers.deepl.com
• DeepL Pro | Translate Text, Word Docs & Other Docs Securely ↗www.deepl.com
• DeepL for Developers ↗www.deepl.com
• Empower your enterprise workflows with Language AI | DeepL ↗www.deepl.com
• What MCP changes about enterprise software ↗www.deepl.com

Company website

deepl.com: product, pricing and policy pages

YC directory mirror

Batch and company name

Social accounts

Accounts the company links, and its posts on X

Human review

Checked by a person

knowledge_base

Last checked 29 Oct 2026. Every field keeps its source and date; unknown means we couldn’t confirm it.