Text-to-speech audio generation
Voice cloning from 5-15 seconds of audio
Emotion-controlled speech ([happy], [sad], etc.)
Word/phoneme timestamps for lip sync
Custom pronunciation with IPA

Models

Model	ID	Latency	Price
TTS-2	`inworld-tts-2`	latest	see pricing
TTS 1.5 Max	`inworld-tts-1.5-max`	legacy	legacy
TTS 1.5 Mini	`inworld-tts-1.5-mini`	legacy	legacy

Minimal Example

import requests, base64, os

response = requests.post(
    "https://api.inworld.ai/tts/v1/voice",
    headers={"Authorization": f"Basic {os.getenv('INWORLD_API_KEY')}"},
    json={"text": "Hello!", "voiceId": "Ashley", "modelId": "inworld-tts-1.5-max"}
)
audio = base64.b64decode(response.json()['audioContent'])

Key Features

15 languages — en, zh, ja, ko, ru, it, es, pt, fr, de, pl, nl, hi, he, ar
Instant cloning — 5-15 seconds audio, no training
Audio markups — [happy], [laughing], [sigh] (English only)
Timestamps — word, phoneme, viseme timing for lip sync
Streaming — /voice:stream endpoint
TTS-2 steering — natural-language bracketed directions such as [say excitedly] or [whisper in a hushed style]
Delivery mode — STABLE, BALANCED, CREATIVE trade consistency for emotional range
Cross-lingual synthesis — reuse one voice across multiple languages; voice localization improves native-sounding output

Release Highlights (TTS-2)

Realtime TTS-2 becomes the new primary model line via modelId="inworld-tts-2".
Steering moves beyond the older fixed emotion tags: free-form bracketed directions can control style, pitch, speed, intensity, and non-verbals.
Multilingual coverage expands with production quality across 15 languages and broader experimental coverage beyond that.
deliveryMode adds a stability-vs-creativity knob, and specifying language matters more for cross-lingual output quality.

Prohibitions

Audio markups work only in English
Use ONE emotion markup at text beginning
Match voice language to text language
Instant cloning may not work for children's voices or unique accents

Models

Minimal Example

Key Features

Release Highlights (TTS-2)

Prohibitions

Links

Topic	Reference
Installation	installation.md
Voice Cloning	cloning.md
Voice Control	voice-control.md
API Reference	api.md

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