Customize

Tailor DeepL translations to your domain with glossaries, style rules, custom instructions, and translation memories.

DeepL’s customization features let you control terminology, style, and consistency across your translations.

What each feature does

Feature	What it controls	How it’s applied
Glossaries	Exact translations for specific terms, like product names or industry vocabulary	Stored on your account; passed per request via glossary_id
Style rules	Formatting conventions (dates, numbers, punctuation) plus stored custom instructions	Stored on your account; passed per request via style_id
Custom instructions	Tone, phrasing, and domain-specific behavior via natural-language directives	Inline per request via custom_instructions, or stored in a style rule list
Translation memories	Reuse of your previously approved translations for matching segments	Stored on your account; passed per request via translation_memory_id
Spoken terms	Recognition of specific terms during Voice API speech transcription	Stored on your account; passed per voice session via spoken_terms_id

Glossaries, style rules, custom instructions, and translation memories work with both text translation and document translation, support all model_type values, and can be combined in a single request. Spoken terms apply to Voice API sessions, where they can be combined with glossaries.

Glossaries and style rules are unique to each of DeepL’s global data centers and are not shared between them. Clients using regional endpoints can’t access glossaries or style rules created in the UI at this time.

Feature guides

Managing Glossaries

Create, edit, retrieve, and delete glossaries with the v3 endpoints, and use them in translations.

Using Style Rules

Build style rule lists with configured rules and custom instructions, and apply them via style_id.

Custom Instructions

Best practices for writing natural-language instructions that produce consistent results.

Using Translation Memories

Retrieve your translation memories and control the matching threshold in translation requests.

Improving Transcription with Spoken Terms

Keep company terms, acronyms, and names transcribed correctly in Voice API sessions.

API reference

Glossaries, style rules, and translation memories each have management endpoints under the API Reference. If you’re still on the deprecated v2 glossary endpoints, see Glossary v2 vs v3 Endpoints for the differences and migration considerations.