Four product lines, one of which most people ever touch

DeepL is an AI translation service, and the company divides it into four products: the translator, an API, a writing assistant called DeepL Write and a conversation tool called DeepL Voice. Day to day most people only meet the first one, the free web translator, where you paste text or upload a file and the translation comes back. Around it sit desktop clients for Windows and macOS, mobile apps, and a browser extension that puts select-to-translate inside an existing workflow.

Text: paste it, or select it and translate in place

The web version is the plainest entry point. You type on the left, the translation appears on the right, and the language pair is detected for you. The official help centre states that the translator covers more than 1000 translation combinations among the languages it lists. The desktop client adds something a web page cannot do: highlight any text, press Ctrl+C twice, and it is translated where it sits, with no switching between windows. On a phone you can also point the camera at printed text and lift the words out of the picture.

Documents come back with the layout intact

This is the part most often underestimated. Drop in a whole document and the translation returns with the original formatting and page layout still in place. The help centre lists the limits format by format, and the list runs past ten entries: Word in .docx and .doc, PowerPoint in .pptx, Excel in .xlsx, PDF, plain text, HTML, XLIFF, SRT subtitles, PNG and JPG images, IDML, XML, JSON, MIF and DITA.

What each format allows differs a good deal. An account without a subscription can translate Word, PowerPoint and PDF files of up to 5MB each, while Excel, plain text and XLIFF need a paid plan. For contracts, manuals and teaching material, where the layout must not break, that restriction weighs more than the wording of the translation itself.

Glossaries keep one term consistent

What usually goes wrong in machine translation is not grammar but consistency: the same term comes out three different ways inside one file. A glossary exists for exactly that. You register the required rendering of product names, job titles and technical terms, and the translator follows the table. The pricing page says the free plan allows one glossary with five terms per language pair; paid plans allow more glossaries and more entries, and support bulk import and sharing through CSV files.

A writing assistant and a spoken translator

DeepL Write is the companion writing tool. According to the help centre it corrects grammar, spelling and punctuation and offers alternative phrasing. It currently covers 11 languages: Chinese, English in both British and American spelling, French, German, Italian, Japanese, Korean, Portuguese, Portuguese for Brazil and Spanish. A visitor who is not signed in can process up to 1,500 characters at a time.

DeepL Voice is built for live conversation. Voice for Meetings puts real-time captions inside Microsoft Teams, Zoom Meetings and Google Meet, and the official figure is more than 40 languages, among them English, French, German, Spanish, Japanese and Chinese. Voice for Conversations handles face-to-face exchange with speech translation on iOS, Android and the web, and the company stresses that meeting data is processed only in memory and deleted when the call ends.

Quotas, and what happens to your text

The pricing page is unusually direct about the limits. The free plan gives 50,000 characters of text translation and one document per month. Paid plans start at 300,000 characters per user each month, the team plan gives 1,000,000, and the enterprise plan is unlimited. For looking things up, reading papers and translating a few pages of product documentation, the free allowance usually holds; a subscription earns its place once whole documents or batches of files become routine.

On the data side, the official statement is that text you type or upload is processed immediately and not stored, and that subscriber data is not used to train models. DeepL holds ISO/IEC 27001 and SOC 2 Type II certification, follows GDPR and HIPAA, and is headquartered in Germany, which also puts it under the EU AI Act.

Closed source, with open client libraries

One thing should be said plainly. The translation service itself is a closed commercial product and the source code is not published, so choosing it means depending on the vendor staying in business. What is open sits on the developer side: the API client libraries are on GitHub under the MIT licence, and six of them are maintained officially, in Python, JavaScript, PHP, .NET, Java and Ruby. The API can also be tried for free, since the Developer plan includes a one-off 1 million characters, and above it sit the monthly Growth plan and a customizable Enterprise API.

A last practical reminder: fluent machine output does not replace a human read. With contracts, legal documents and anything published outside the company, treat the translation as an aid to quick understanding and let the original govern.

What a translation tool changes in the end is not the wording but your willingness to read foreign text at all. A formatted translation sitting beside the original is what gives a reader the patience to look back at the source, and that is why whole-document translation matters more than it first appears.