Controlling Writing Style and Tone

Steer Write API output with the writing_style and tone parameters: available values, per-language support, and prefer_ fallback behavior.

The /v2/write/rephrase endpoint accepts two parameters that steer how your text is rewritten: writing_style changes the register of the text, and tone changes how it sounds. A request can include one or the other, but not both.

Writing styles

Value	Fallback variant
simple	prefer_simple
business	prefer_business
academic	prefer_academic
casual	prefer_casual
default	(same as omitting writing_style)

Tones

Value	Fallback variant
enthusiastic	prefer_enthusiastic
friendly	prefer_friendly
confident	prefer_confident
diplomatic	prefer_diplomatic
default	(same as omitting tone)

Language support and fallback behavior

Styles and tones are currently supported for the target languages de, en-GB, en-US, es, fr, it, pt-BR, and pt-PT. To check support dynamically, call GET /v3/languages?resource=write and look for the writing_style or tone feature key on the target language.

The prefer_ variants fall back to default when the target language doesn’t support styles or tones; the non-prefixed values return an HTTP 400 error in that case. Use the prefer_ variants when you don’t set a target_lang explicitly, since the detected language may not support styles or tones.

Example

This request rewrites the same text in a diplomatic tone:

Sample request

curl -X POST https://api.deepl.com/v2/write/rephrase \
  --header "Authorization: DeepL-Auth-Key $API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
    "text": [
      "Your proposal misses the point entirely."
    ],
    "target_lang": "en-US",
    "tone": "prefer_diplomatic"
}'

Sample response

{
  "improvements": [
    {
      "text": "It seems that your proposal may not fully capture the essence of the issue at hand.",
      "detected_source_language": "en",
      "target_language": "en-US"
    }
  ]
}

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