Voice AI indistinguishable from humans.

SpeechifyAI is a research lab advancing the science of speech synthesis, voice cloning, emotional expression, and voice agents.

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First request

Choose parameters inline, then copy the request.

bash
curl -X POST https://api.speechify.ai/v1/audio/speech \
-H "Authorization: Bearer $SPEECHIFY_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"input": "The quick brown fox jumped over the lazy dog",
"model": "",
"voice_id": "",
"audio_format": "mp3"
}'
curl -X POST https://api.speechify.ai/v1/audio/speech \
  -H "Authorization: Bearer $SPEECHIFY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": "The quick brown fox jumped over the lazy dog",
    "model": "simba-3.0",
    "voice_id": "george",
    "audio_format": "mp3"
  }'

POST /v1/audio/speech

Run the request, then play the result.

Idle

Response appears here after the request completes.

Selected sample: Simba 3.0, George, neutral.

Featured Model

Simba 3.0

Our flagship streaming-native model. Lower time-to-first-byte than previous generations, with finer-grained emotional control, zero-shot voice cloning, and SSML prosody. Language coverage is expanding.

Streaming-native architecture Emotional expression Zero-shot voice cloning SSML prosody control
Explore our models

“Every moment of light and dark is a miracle.”

Technology

Reference
Clone

Zero-Shot Voice Cloning

Clone any voice from a short reference clip. Simba captures speaker identity — timbre, cadence, and micro-expressions — from as little as 10 seconds of audio.

Neutral
Happy
Sad
Excited
Calm

Emotion Control

Generate the same text with different emotional expressions. Simba models emotion at the prosody level — not just speed and pitch, but the subtle rhythmic and tonal patterns that convey feeling.

en-US
es-MX
fr-FR
de-DE
ja-JP
pt-BR

Multilingual Synthesis

Native-quality speech across 30+ locales. Each language uses voices recorded in that locale for natural pronunciation and prosody, with mixed-language input handled automatically.

Build with our models

A single API to access all Speechify models. Streaming, voice cloning, emotion control — everything in a few lines of code.

Explore the API Documentation
bash 
curl -X POST https://api.speechify.ai/v1/audio/speech \
  -H "Authorization: Bearer $SPEECHIFY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": "Hello, world.",
    "voice_id": "george",
    "audio_format": "mp3"
  }'

SpeechifyAI is building the future of voice

We're a research lab focused on speech synthesis, voice understanding, and audio intelligence. Our work spans fundamental research in neural speech generation, zero-shot voice cloning, and emotional expression modeling — turning the nuances of human speech into something machines can learn and reproduce.

Learn about our lab