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POST
/
tts
/
bytes
Text to Speech (Bytes)
curl --request POST \
  --url https://api.cartesia.ai/tts/bytes \
  --header 'Cartesia-Version: <cartesia-version>' \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "model_id": "<string>",
  "transcript": "<string>",
  "voice": {
    "mode": "id",
    "id": "<string>",
    "__experimental_controls": {
      "speed": 123,
      "emotion": [
        "anger:lowest"
      ]
    }
  },
  "output_format": {
    "container": "raw",
    "encoding": "pcm_f32le",
    "sample_rate": 123,
    "bit_rate": 123
  },
  "language": "en",
  "duration": 123,
  "speed": "slow"
}
'
"<string>"

Documentation Index

Fetch the complete documentation index at: https://docs.cartesia.ai/llms.txt

Use this file to discover all available pages before exploring further.

Authorizations

​
X-API-Key
string
header
required

Headers

​
Cartesia-Version
enum<string>
required

API version header.

Available options:
2024-06-10,
2024-11-13,
2025-04-16,
2026-03-01
Example:

"2024-06-10"

Body

application/json
​
model_id
string
required

The ID of the model to use for the generation. See Models for available models.

​
transcript
string
required
​
voice
TTSRequestIdSpecifier · object
required
​
output_format
RawOutputFormat · object
required
​
language
enum<string> | null

The language that the given voice should speak the transcript in.

Options: English (en), French (fr), German (de), Spanish (es), Portuguese (pt), Chinese (zh), Japanese (ja), Hindi (hi), Italian (it), Korean (ko), Dutch (nl), Polish (pl), Russian (ru), Swedish (sv), Turkish (tr).

Available options:
en,
fr,
de,
es,
pt,
zh,
ja,
hi,
it,
ko,
nl,
pl,
ru,
sv,
tr
​
duration
number<double> | null

The maximum duration of the audio in seconds. You do not usually need to specify this. If the duration is not appropriate for the length of the transcript, the output audio may be truncated.

​
speed
enum<string> | null
deprecated

This feature is experimental and may not work for all voices.

Speed setting for the model. Defaults to normal.

Influences the speed of the generated speech. Faster speeds may reduce hallucination rate.

Available options:
slow,
normal,
fast

Response

200 - audio/*

Audio bytes

The response is of type file.