Engage every user with the #1 ranked, most natural Voice AI
One API. Streaming, cloning, voice design.
Stream audio chunks back as the model generates them. Sub-200ms first-chunk latency keeps the conversation feeling natural.
curl -X POST https://api.inworld.ai/tts/v1/voice:stream \
-H "Authorization: Basic $INWORLD_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"text": "Hi! What can I help you with today?",
"voice_id": "Clive",
"model_id": "inworld-tts-2",
"audio_config": {
"audio_encoding": "OGG_OPUS",
"sample_rate_hertz": 16000
}
}'curl -X POST https://api.inworld.ai/tts/v1/voice:stream \
-H "Authorization: Basic $INWORLD_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"text": "Hi! What can I help you with today?",
"voice_id": "Clive",
"model_id": "inworld-tts-2",
"audio_config": {
"audio_encoding": "OGG_OPUS",
"sample_rate_hertz": 16000
}
}'One API. Streaming, cloning, voice design.
Stream audio chunks back as the model generates them. Sub-200ms first-chunk latency keeps the conversation feeling natural.
The top ranked TTS in the world. Proven by real users.
3 of the top 5 models on Artificial Analysis are Inworld. Blind tests by thousands of real users, not internal evals. Realtime TTS 1.5 Max delivers over 30% more expressiveness than previous models, with optimized stability to eliminate hallucinations and artifacts.
Test out QualityThe top ranked TTS in the world. Proven by real users.
3 of the top 5 models on Artificial Analysis are Inworld. Blind tests by thousands of real users, not internal evals. Realtime TTS 1.5 Max delivers over 30% more expressiveness than previous models, with optimized stability to eliminate hallucinations and artifacts.
Test out QualityClone any voice. Localize to any language.
Create a custom voice from 15 seconds of audio, then localize it to speak over 100 languages as a native speaker — same identity, no accent carryover. Production-ready voices you can use in the Playground or via API.
- Instant cloning: 15 seconds of audio → ready in seconds
- Localize: one voice, native delivery in over 100 languages
Clone any voice. Localize to any language.
Create a custom voice from 15 seconds of audio, then localize it to speak over 100 languages as a native speaker — same identity, no accent carryover. Production-ready voices you can use in the Playground or via API.
- Instant cloning: 15 seconds of audio → ready in seconds
- Localize: one voice, native delivery in over 100 languages
Describe any voice. Generate it instantly.
Skip recording entirely. Describe accent, age, tone, and energy in natural language, and Inworld renders a production-ready voice on the fly. Pick a preset on the card to hear how a single sentence becomes a finished voice.
- No audio sample required — pure natural-language description
- Per-preset playback so you can compare styles before generating
- Same voice IDs work across the TTS API, Playground, and Realtime
Describe any voice. Generate it instantly.
Skip recording entirely. Describe accent, age, tone, and energy in natural language, and Inworld renders a production-ready voice on the fly. Pick a preset on the card to hear how a single sentence becomes a finished voice.
- No audio sample required — pure natural-language description
- Per-preset playback so you can compare styles before generating
- Same voice IDs work across the TTS API, Playground, and Realtime
Realtime latency. Instant responses.
Built for realtime from the ground up — audio generates the instant it's synthesized via WebSocket. No buffering delay. Comparable latency to competitors at a fraction of the cost.
- First-chunk audio in a fraction of a humanlike response time
- Streaming-native via WebSocket
- Consistent P90 performance under production load
Realtime latency. Instant responses.
Built for realtime from the ground up — audio generates the instant it's synthesized via WebSocket. No buffering delay. Comparable latency to competitors at a fraction of the cost.
- First-chunk audio in a fraction of a humanlike response time
- Streaming-native via WebSocket
- Consistent P90 performance under production load
Direct the voice. Match the moment.
Add bracketed instructions anywhere in your text and Realtime TTS-2 adjusts the utterance. Pair with various non-verbals and adjustable pauses for delivery that matches the moment, not just the words.
- Natural-language steering for tone, speed, volume, vocal style, and pauses
- Five reliable non-verbal cues that render as the actual sound, not text
- Mid-utterance adjustment — no separate prompt engineering pipeline
Direct the voice. Match the moment.
Add bracketed instructions anywhere in your text and Realtime TTS-2 adjusts the utterance. Pair with various non-verbals and adjustable pauses for delivery that matches the moment, not just the words.
- Natural-language steering for tone, speed, volume, vocal style, and pauses
- Five reliable non-verbal cues that render as the actual sound, not text
- Mid-utterance adjustment — no separate prompt engineering pipeline
over 100 languages. Native-speaker quality.
English, Spanish, French, Korean, Chinese, Hindi, Japanese, German, and more. Native-speaker quality in every language with cross-lingual cloning. Deploy globally without separate pipelines.
Test out Languages- English
- Spanish
- French
- German
- Japanese
- Korean
- English
- Spanish
- French
- German
- Japanese
- Korean
over 100 languages. Native-speaker quality.
English, Spanish, French, Korean, Chinese, Hindi, Japanese, German, and more. Native-speaker quality in every language with cross-lingual cloning. Deploy globally without separate pipelines.
Test out LanguagesStarting at $15 per million characters.
Realtime TTS 1.5 Mini at $15/million characters. Realtime TTS 1.5 Max and Realtime TTS-2 at $25/million. Comparable providers charge $120/million ($0.12/min) — Inworld is up to 87% cheaper at scale.
View pricing
Starting at $15 per million characters.
Realtime TTS 1.5 Mini at $15/million characters. Realtime TTS 1.5 Max and Realtime TTS-2 at $25/million. Comparable providers charge $120/million ($0.12/min) — Inworld is up to 87% cheaper at scale.
View pricingBuilt for voice-first applications
Full breakdown
Research
Integrations
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FAQs
Instant (zero-shot) voice cloning
- Available to all users in the Portal
- Creates a custom voice from just 15 seconds of audio
- Ready to use in minutes
Professional voice cloning
- Fine-tuned using 30+ minutes of clean audio (minimum ~5 minutes, 20+ minutes recommended for best results)
- Recommended for uncommon voice types such as children's voices or unique accents, where instant cloning may not perform well
- Currently available by contacting the Inworld sales team
Voice parameters
- Temperature: Controls expressiveness and randomness
- Talking speed: 0.5× to 1.5× of the native speaking rate
- word or character tokens
- start and end timestamps (in seconds)
- structured alignment data matching the generated audio
- phoneme-level timing and viseme symbols for lip-sync (TTS 1.5 models only)