#1 ranked, most natural voice AI.
Human-like expression and realtime latency that feels like a real conversation. Custom voices with instant cloning. 15+ languages. A fraction of the cost.
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-1.5-max", "audio_config": {
"audio_encoding": "OGG_OPUS",
"sample_rate_hertz": 16000
}
}'#1
Ranked Quality
Realtime
Latency
15+
Languages
Try it live
Type or paste text, pick a voice, hear it instantly.
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. TTS-1.5 Max delivers over 30% more expressiveness than previous models, with optimized stability to eliminate hallucinations and artifacts.
Test quality in Playground#1
Ranked on
Artificial Analysis
#1 Inworld TTS 1.5 Max
ELO 1,215
#2 ElevenLabs Eleven v3
ELO 1,179
#3 Inworld TTS 1 Max
ELO 1,169
#4 MiniMax Speech 2.8 HD
ELO 1,169
#5 Inworld TTS 1.5 Mini
ELO 1,165
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. TTS-1.5 Max delivers over 30% more expressiveness than previous models, with optimized stability to eliminate hallucinations and artifacts.
Test quality in Playground#1
Ranked on
Artificial Analysis
#1 Inworld TTS 1.5 Max
ELO 1,215
#2 ElevenLabs Eleven v3
ELO 1,179
#3 Inworld TTS 1 Max
ELO 1,169
#4 MiniMax Speech 2.8 HD
ELO 1,169
#5 Inworld TTS 1.5 Mini
ELO 1,165
Instant custom voice creation.
Create custom voices instantly from 15 seconds of audio or a text description. Fine-tune with professional voice cloning for maximum fidelity. All methods produce production-ready voices you can use in the Playground or via API.
- Instant cloning: 15 seconds of audio → ready in seconds
- Text-based voice design for full creative control
- Professional cloning: 30+ minutes for maximum fidelity
15s audio sample or text description
Voice created
"my-cloned-voice"
Use via API or Playground
15s audio sample or text description
Voice created
"my-cloned-voice"
Use via API or Playground
Instant custom voice creation.
Create custom voices instantly from 15 seconds of audio or a text description. Fine-tune with professional voice cloning for maximum fidelity. All methods produce production-ready voices you can use in the Playground or via API.
- Instant cloning: 15 seconds of audio → ready in seconds
- Text-based voice design for full creative control
- Professional cloning: 30+ minutes for maximum fidelity
Realtime latency. Feels instant.
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 first-chunk latency
~130ms
TTS-1.5 Mini
~250ms
TTS-1.5 Max
350ms
Human
Realtime latency. Feels instant.
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 first-chunk latency
~130ms
TTS-1.5 Mini
~250ms
TTS-1.5 Max
350ms
Human
15+ 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.
Explore voices
🇺🇸Hello world🇨🇳你好世界🇮🇳नमस्ते दुनिया🇪🇸Hola mundo🇫🇷Bonjour le monde🇰🇷안녕하세요 세계🇮🇹Ciao mondo🇯🇵こんにちは世界
And more
🇺🇸Hello world🇨🇳你好世界🇮🇳नमस्ते दुनिया🇪🇸Hola mundo🇫🇷Bonjour le monde🇰🇷안녕하세요 세계🇮🇹Ciao mondo🇯🇵こんにちは世界
And more
15+ 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.
Explore voicesStarting at $15 per million characters.
TTS-1.5 Mini starts at $15/million characters. TTS-1.5 Max at $30/million. The next best option is over $150. Scale to millions of users without scale-related cost anxiety.
View pricingTTS-1.5
Inworld
$15
ElevenLabs
>$150
Starting at $15 per million characters.
TTS-1.5 Mini starts at $15/million characters. TTS-1.5 Max at $30/million. The next best option is over $150. Scale to millions of users without scale-related cost anxiety.
View pricingTTS-1.5
Inworld
$15
ElevenLabs
>$150
Built for voice-first applications
Interactive, real-time, and voice-driven experiences. Not batch processing.
Voice Agents
Sub-200ms latency and streaming-native architecture for conversational AI that feels real.
Integrate TTS in minutes
Real code you can copy and run.
Integrate Inworld TTS streaming into my app for real-time audio playback.
Read the linked documentation below before generating code — it contains the complete API specification, authentication details, and working examples.
## Configuration
- Model: inworld-tts-1.5-max
- Voice: Clive
- Audio output: LINEAR16 streamed as NDJSON chunks
- Speaking rate: 1
## What to build
- POST to https://api.inworld.ai/tts/v1/voice:stream
- Read the NDJSON response stream — each line contains { "result": { "audioContent": "<base64>" } }
- Decode and play each audio chunk as it arrives for low-latency playback
## Authentication
Pass the API key in the Authorization header:
Authorization: Basic <YOUR_API_KEY>
IMPORTANT: Do NOT hardcode the API key. Store it in an environment variable.
## Reference documentation
- TTS Overview: https://docs.inworld.ai/tts/tts
- HTTP Streaming API: https://docs.inworld.ai/api-reference/ttsAPI/texttospeech/synthesize-speech-stream
- WebSocket Streaming API: https://docs.inworld.ai/api-reference/ttsAPI/texttospeech/synthesize-speech-websocket
## MCP Server
For full API context in your coding agent, add: https://docs.inworld.ai/mcpFull breakdown
Feature
TTS-1.5 Max
TTS-1.5 Mini
Best for
Most applications
Latency-critical applications
Pricing
$30/million characters
$15/million characters
P90 latency
<250ms
<130ms
Quality
Maximum expressiveness and stability
High expressiveness
Multilingual
15 languages
15 languages
Voice cloning
Professional voice cloning
Character, word, viseme and phoneme timestamps
Custom pronunciation
On-premise
Zero data retention
We recommend TTS-1.5 Max for most use cases. The enhanced stability and quality are worth the marginal latency tradeoff for the vast majority of applications.
FAQ
Getting started is simple. You can try Inworld TTS instantly in the TTS Playground, where you can test voices, adjust settings, and experiment with features like instant voice cloning.
When you're ready to integrate TTS into your application, you can follow the Developer Quickstart to make your first API request in minutes. Just create an API key in the Inworld Portal, then synthesize speech with a single POST request. Inworld supports multiple output formats, including MP3, Linear PCM (WAV), and Opus, making it easy to integrate with almost any system.
Inworld TTS is evaluated through blind listening tests by thousands of real users. TTS-1.5 Max delivers over 30% more expressiveness than its predecessor, with optimized stability and natural conversational delivery.
For most applications: TTS-1.5 Max (~250ms latency, $30/1M characters)
TTS-1.5 Max offers the best balance of quality and speed. The enhanced stability means fewer edge cases, better voice cloning fidelity, and more consistent output across languages.
For latency-critical applications: TTS-1.5 Mini (~130ms latency, $15/1M characters)
Choose TTS-1.5 Mini only if minimal latency is your absolute top priority — for example, real-time gaming or ultra-responsive voice agents where every millisecond matters.
TTS-1.5 Mini achieves ~130ms first-chunk latency. TTS-1.5 Max delivers ~250ms with enhanced stability and quality. Both support real-time streaming via WebSocket. For most applications, we recommend TTS-1.5 Max — the quality improvement is worth the marginal latency tradeoff.
Yes. Inworld provides two types of voice cloning:
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
Both methods allow you to use your cloned voice directly in the Playground or via API using its unique voiceId.
Inworld TTS-1.5 supports 15 languages: English, Spanish, French, Korean, Dutch, Chinese, German, Italian, Japanese, Polish, Portuguese, Russian, Hindi, Arabic, and Hebrew.
For multilingual applications, we recommend TTS-1.5 Max for the best pronunciation, intonation, and naturalness across all supported languages.
Absolutely. Inworld TTS provides several ways to customize how the speech sounds:
Voice parameters
- Temperature: Controls expressiveness and randomness
- Talking speed: 0.5× to 1.5× of the native speaking rate
Yes. Inworld TTS supports timestamp alignment for word, character, phoneme, and viseme level synchronization. This can be helpful for subtitles, captions, lipsync, and more.
You can enable it in your API request by setting timestampType to WORD or CHARACTER.
The API response includes:
- 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)
Timestamp alignment currently supports English, with other languages available experimentally. Note that enabling timestamps currently adds roughly 100 ms of additional latency.
TTS-1.5 is a major update delivering improvements across speed, quality, and accessibility:
The Fastest: ~130ms first-chunk latency — the fastest realtime TTS available. TTS-1.5 Max delivers ~250ms with enhanced quality.
The Highest Quality: Optimized stability to minimize hallucinations, cutoffs, and artifacts. Over 30% more expressive than TTS-1.
The Most Accessible: 15 languages (including Hindi), enhanced voice cloning, on-premise H100/B200 deployment, and 25x lower cost than alternatives.
Which model should I use? For most applications, we recommend TTS-1.5 Max. Use TTS-1.5 Mini only when minimal latency is the top priority.
Yes. Inworld provides a free, open-source ElevenLabs Migration Tool that lets you batch-transfer your custom voice clones from ElevenLabs to Inworld. The tool automatically downloads your ElevenLabs voice samples, handles audio processing (format conversion, padding, and trimming), and re-clones them in Inworld.
The migration runs entirely on your local machine with direct API communication — no data is proxied through any intermediary servers. You can also preview your migrated voices with Inworld TTS before finalizing.
Try Inworld TTS now
Get started with TTS-1.5 Max. The best balance of quality and speed for most applications.