Eleven v4 Turbo - Unifically

Eleven v4 Turbo is the real-time model of the ElevenLabs Eleven v4 family, released on September 28, 2026, with a median inference latency of about 100 ms. It takes the same input as Eleven v4: one voice or a multi-speaker dialogue, audio tags like [whispering] and [laughing], per-request voice cloning, and 70+ languages. Each request takes up to 10,000 characters and is billed on the characters spoken. Try it in the browser: Eleven v4 Turbo API page.

Model

elevenlabs/eleven-v4-turbo

Parameters

Send either text + voice (one voice) or dialogue (several speakers), never both.

Parameter	Type	Required	Default	Description
`text`	string	With `voice`	-	Text to speak, up to 10,000 characters. Supports audio tags such as `[whispering]` or `[laughing]`
`voice`	string or array	With `text`	-	Voice to use — see Voice Options
`dialogue`	array	Instead of `text` + `voice`	-	Multi-speaker conversation — see Dialogue Object
`language_code`	string	No	auto-detect	ISO 639-1 language code (e.g. `en`, `es`). Omit to detect the language from the text
`seed`	integer	No	-	Seed for reproducible generation (0–4294967295)
`output_format`	string	No	`mp3_44100_128`	Audio output format (see formats below)
`voice_settings`	object	No	-	`stability` and `similarity_boost` (see below)
`with_timestamps`	boolean	No	`false`	Text mode only. Return character alignment and word timings alongside the audio

Eleven v4 Turbo has no style, speed or use_speaker_boost settings and does not support SSML. Direct the delivery with audio tags in the text instead.

Voice Options

In text mode, voice accepts two forms:

Form	Example	Meaning
Voice ID	`"voice": "21m00Tcm4TlvDq8ikWAM"`	An available voice from `GET /v1/resources/elevenlabs/voices`.
Sample URLs	`"voice": ["https://.../a.mp3", "https://.../b.mp3"]`	A voice cloned from these samples for this request only, then deleted. The caller hosts the samples; Unifically does not retain them.

On-Demand Voice Samples

All samples must contain the same speaker.
Up to 25 sample URLs are accepted per request.
Sample URLs must be direct downloads — redirects and link shorteners are rejected.
Supported audio formats: mp3, wav, ogg, opus, m4a, flac, webm.
Voice IDs must come from GET /v1/resources/elevenlabs/voices; IDs from a separate ElevenLabs account are not available to Unifically.

Dialogue Object

Each item in the dialogue array contains:

Parameter	Type	Required	Description
`text`	string	Yes	This speaker’s line. Supports audio tags such as `[excited]`
`voice`	string	Yes	Voice ID for this speaker

Dialogue returns one audio file for the whole conversation. with_timestamps and sample-URL voices are text-mode only.

voice_settings

Field	Type	Default	Description
`stability`	number	`0.5`	0–1. Lower = more expressive and varied, higher = steadier delivery
`similarity_boost`	number	`0.75`	0–1. How closely the output adheres to the reference voice. Very high values can sound less natural

Output Formats

Format	Description
`mp3_22050_32`	MP3 22.05kHz 32kbps
`mp3_44100_64`	MP3 44.1kHz 64kbps
`mp3_44100_96`	MP3 44.1kHz 96kbps
`mp3_44100_128`	MP3 44.1kHz 128kbps (default)
`mp3_44100_192`	MP3 44.1kHz 192kbps
`opus_48000_32`	Opus 48kHz 32kbps
`opus_48000_64`	Opus 48kHz 64kbps
`opus_48000_96`	Opus 48kHz 96kbps
`opus_48000_128`	Opus 48kHz 128kbps
`opus_48000_192`	Opus 48kHz 192kbps
`pcm_16000`	Raw PCM 16kHz
`pcm_22050`	Raw PCM 22.05kHz
`pcm_24000`	Raw PCM 24kHz
`pcm_44100`	Raw PCM 44.1kHz
`pcm_48000`	Raw PCM 48kHz
`wav_44100`	WAV 44.1kHz
`ulaw_8000`	μ-law 8kHz (Twilio)
`alaw_8000`	A-law 8kHz

Resources

Get available voices from the Resources API:

GET /v1/resources/elevenlabs/voices

Example — one voice with timestamps

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "elevenlabs/eleven-v4-turbo",
    "input": {
      "text": "[whispering] The door was already open... Someone had been here.",
      "voice": "21m00Tcm4TlvDq8ikWAM",
      "with_timestamps": true
    }
  }'

Example — dialogue

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "elevenlabs/eleven-v4-turbo",
    "input": {
      "dialogue": [
        { "text": "[excited] You will not believe what I found in the attic.", "voice": "21m00Tcm4TlvDq8ikWAM" },
        { "text": "[laughing] Please tell me it is not another box of cables.", "voice": "AZnzlk1XvdvUeBnXmlld" }
      ],
      "voice_settings": { "stability": 0.4 }
    }
  }'

Response

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "processing"
  }
}

Completed Response

Poll GET /v1/tasks/{task_id} until status is completed:

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "completed",
    "output": {
      "audio_url": "https://files.unifically.com/audio/abc123.mp3",
      "alignment": {
        "characters": ["T", "h", "e"],
        "character_start_times_seconds": [0.0, 0.07, 0.12],
        "character_end_times_seconds": [0.07, 0.12, 0.2]
      },
      "normalized_alignment": { "...": "same shape, for the spoken (normalized) text" },
      "words": [
        { "word": "The", "start": 0.0, "end": 0.2 },
        { "word": "door", "start": 0.26, "end": 0.55 }
      ]
    }
  }
}

alignment, normalized_alignment and words appear only when with_timestamps is true in text mode.
Without timestamps, and for dialogue, the output contains only audio_url.

Volume discounts are available for almost all models. Reach out at contact@unifically.com to discuss custom pricing.

​Model

​Parameters

​Voice Options

​On-Demand Voice Samples

​Dialogue Object

​voice_settings

​Output Formats

​Resources

​Example — one voice with timestamps

​Example — dialogue

​Response

​Completed Response

Model

Parameters

Voice Options

On-Demand Voice Samples

Dialogue Object

voice_settings

Output Formats

Resources

Example — one voice with timestamps

Example — dialogue

Response

Completed Response