Soniox

Soniox is a multilingual voice AI platform that provides a unified API for real-time speech-to-text, text-to-speech, and speech translation across 60+ languages, designed for live conversational applications.

What is Soniox?

Soniox is a cloud-based voice platform that processes audio input (live streams or recorded files) and outputs accurate transcriptions, natural-sounding synthesized speech, or real-time translations. It is developed by Soniox and currently marketed as version 5 (v5), with a newly introduced Voice Cloning capability now available for text-to-speech.

Key Features

• Speech-to-Text API — Real-time transcription with sub-200ms latency, native-speaker accuracy across 60+ languages, and support for multi-speaker conversations, code-switching, high-noise environments, and domain-specific vocabulary (e.g., “Nakamura Pharma”).
• Text-to-Speech API — Natural high-fidelity speech generation in 60+ languages, with precise handling of alphanumerics, foreign names (e.g., “Dr. Okafor”), language switching, and ultra-low-latency streaming that begins output from the first words.
• Speech Translation API — Real-time translation across 3,600 language pairs (e.g., Thai→Kazakh, Polish→Croatian), with low-latency output before the source sentence finishes and context-aware handling of code-switching.
• Voice Cloning — Newly launched feature for cloning voices, integrated into the text-to-speech API.
• Low-latency streaming — Speech-to-text achieves sub-200ms latency; text-to-speech starts audio generation from the first few words, enabling near-instant interaction.
• Multilingual support — Over 60 languages for both recognition and synthesis, with seamless switching between languages within a single utterance.

Who is it for?

Soniox is trusted by teams building global voice products, including:

• Conversational AI agents (e.g., Retell AI, Vapi) — power real-time voice chatbots with streaming STT/TTS.
• Meeting transcription and note-taking (e.g., Fireflies.ai, Jamie.ai) — transcribe multi-speaker meetings with high accuracy on names and numbers.
• Customer service and call center platforms (e.g., Skit.ai, InteractCX) — enable multilingual voice IVR and live translation.
• Dictation tools (e.g., Wispr Flow) — convert speech to text with low latency across 60+ languages.

What can you do with Soniox?

• Build real-time voice agents — Stream audio to the Speech-to-Text API for instant transcription, then synthesize responses via Text-to-Speech, with support for code-switching (e.g., confirming an appointment for “Dr. Okafor”).
• Transcribe and translate live meetings — Use speech translation to convert a Polish speaker’s words into Croatian in real time, with speaker diarization and multi-language support.
• Create multilingual voice interfaces — Integrate with platforms like Livekit, Krisp, or Agora to add speech recognition and synthesis to apps, games, or IoT devices.
• Generate synthetic speech for content — Produce high-fidelity audio for voiceovers, audiobooks, or assistants, with voice cloning for personalized voices.

Pricing

Soniox offers a freemium pricing model. Specific usage limits and paid tiers are available on the Soniox website.

FAQ

What languages does Soniox support?

Soniox supports over 60 languages for speech-to-text and text-to-speech, and 3,600 language pairs for speech translation, including low-resource pairs like Gujarati→Swedish and Azerbaijani→Welsh.

Does Soniox support real-time streaming?

Yes. Speech-to-text operates with sub-200ms latency, and text-to-speech begins output from the first few words of the input, enabling live interaction.

Is there a free tier?

Yes, Soniox offers a freemium plan with limited usage. Exact quotas are listed on the website.