Omni Voice
AI Voice Cloning and Text-to-Speech Platform
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What is Omni Voice?
OmniVoice is a free, open-source AI voice generator and text-to-speech (TTS) tool powered by one unified model that supports 646 languages and dialects without requiring separate language pack installs. It converts any text into natural-sounding speech in seconds, handling punctuation, abbreviations, and numerals automatically. The tool is developed by the k2-fsa research team and trained on 581,000 hours of open-source speech data under the Apache 2.0 license.
The platform offers four core capabilities in one unified model: natural text-to-speech across 646 languages, zero-shot voice cloning from 3–25 second audio samples, AI voice design from text prompts alone, and expressive speech with emotional tags like [laughter], [sigh], and [gasp]. Voice cloning works cross-lingually, meaning you can clone a voice from an English recording and generate speech in Japanese, Arabic, or Swahili in the same voice without per-language samples. Voice Design lets users create custom voices by describing age, pitch, accent, and style in plain text.
OmniVoice is built for audiobook and podcast production, game NPC dialogue, global localization, e-learning and language tutoring, customer support and IVR systems, and accessibility/assistive technology. It achieves 2.85% word error rate in a 24-language benchmark compared to 10.95% for ElevenLabs, and scores 0.830 on speaker similarity versus 0.655 for ElevenLabs. The tool runs at RTF 0.022 on batch inference, generating a 60-second audio file in roughly 1.3 seconds.
Users can export audio as WAV (48kHz lossless) or MP3 (compressed), adjust speaking speed from 0.5× to 2.0×, and filter presets by language, gender, accent, and tone. The tool supports NVIDIA GPU (CUDA 12.8), Apple Silicon, and CPU, with GPU recommended for production use at ~45× real-time speed on an H20 GPU.
Omni Voice pricing
Pricing model: Freemium
OmniVoice is completely free and open-source under Apache 2.0 with no subscription fee, no character limits per generation, and no hidden costs. No account or signup is required to use the web demo. For those who prefer paid cloud credits, one-time credit plans are available: Basic at $9.9 includes 99 credits ($0.10 per credit), Pro at $29.9 includes 350 credits ($0.085 per credit), and Business at $49.9 includes 600 credits ($0.083 per credit). All plans include all 646 languages, Zero-Shot Voice Cloning, MP3 & WAV download, commercial use license, and email support. Pro adds priority queue speed and priority support. Business adds batch processing, fastest queue, and up to 5 concurrent jobs. Credits never expire. A 7-day money-back guarantee is available.
Omni Voice pros
- Supports 646 languages with one unified model
- Zero-shot voice cloning from 3–25 second samples
- Cross-lingual cloning works across all 646 languages
- Voice Design creates voices from text prompts alone
- Expressive tags for [laughter], [sigh], [gasp]
- Completely free with no subscription required
- Open source under Apache 2.0 license
- No character limits per generation
- No account or signup needed for web demo
- 2.85% word error rate vs 10.95% for ElevenLabs
- 0.830 speaker similarity vs 0.655 for ElevenLabs
- Fast inference at ~45× real-time on GPU
- Exports lossless WAV at 48kHz and MP3
- Adjustable speaking speed from 0.5× to 2.0×
- Commercial use license included
- Robust performance with noisy recordings
- Automatic transcription with Whisper ASR
- Self-hostable on your own server at zero cost
- OpenAI-compatible REST API wrapper available
- Works on NVIDIA GPU, Apple Silicon, and CPU
Omni Voice cons
- MPS broken on Apple Silicon (must use CPU)
- Requires PyTorch installed for self-hosting
- Reference clips need clean single-speaker audio
- Long scripts over 500 words need segmentation
- No mobile app available
- Standard queue speed on basic free tier
- GPU recommended for production use
- Learning curve for expressive tag usage
Frequently asked questions about Omni Voice
What is OmniVoice?
OmniVoice is a free, open-source AI voice generator that supports 646 languages. It converts text to natural-sounding speech, clones voices from a short audio sample using zero-shot Voice Cloning, or creates a voice from a text description alone using Voice Design. Developed by the k2-fsa research team and trained on 581,000 hours of open-source speech data.
Is OmniVoice free to use?
Yes. OmniVoice is released under Apache 2.0 — free for personal and commercial use, with no subscription fee, no character limits, and no hidden costs. No account or signup is required for the web demo. You can also self-host it on your own server at zero cost.
How many languages does OmniVoice support?
OmniVoice supports 646 languages — one of the broadest language coverages available in zero-shot TTS. This includes major languages like English, Japanese, Spanish, and Arabic, as well as hundreds of low-resource languages most TTS tools don't support. All languages work with one unified model without separate language pack installs.
How does zero-shot voice cloning work?
Voice cloning in OmniVoice is zero-shot: provide a 3–25 second audio reference, and OmniVoice immediately extracts the speaker's voice profile to generate new speech — no model training required. It also works cross-lingually: clone a voice from an English recording and synthesize it in any other supported language without per-language samples.
How does OmniVoice compare to ElevenLabs?
In an independent 24-language benchmark, OmniVoice achieved 2.85% word error rate vs. ElevenLabs' 10.95%, and higher speaker similarity (0.830 vs. 0.655). OmniVoice also supports 646 languages vs. ElevenLabs' 32, and is free and open source vs. $5–$1,320/month. OmniVoice also offers Voice Design (text-only voice creation) and cross-lingual cloning, which ElevenLabs lacks or has limited support for.
What is Voice Design?
Voice Design lets you create a voice without any audio reference — just describe it in text like 'female, low pitch, British accent, calm.' OmniVoice generates a matching speaker voice from the description. This feature is unique to OmniVoice and not available in ElevenLabs or PlayHT. You can describe age, pitch, accent, and style in plain text to generate a reusable synthetic speaker identity.
Can I use OmniVoice commercially?
Yes. Apache 2.0 explicitly permits commercial use. OmniVoice was also trained exclusively on open-source datasets, so there are no hidden licensing risks. All paid credit plans also include a commercial use license.
What hardware does OmniVoice run on?
OmniVoice supports NVIDIA GPU (CUDA 12.8), Apple Silicon, and CPU. For production use, a GPU is recommended — on an H20 GPU it runs at ~45× real-time speed. Note that MPS is broken on Apple Silicon, so you must use CPU instead on Apple devices.
What audio formats can I export?
OmniVoice exports audio as WAV (48kHz lossless) or MP3 (compressed, lighter files). You can download the audio file directly or copy a share link to send to anyone. Supported reference audio formats for voice cloning include PCM, WAV, MP3, FLAC, and OPUS.
How do I get the best results with OmniVoice?
Use punctuation intentionally to shape pacing and prosody. Record clean reference clips — 5-10 seconds of clean single-speaker audio is the practical sweet spot for cloning. Write for speech, not reading, by formatting acronyms, numbers, and dates the way you want listeners to hear them. Change one variable at a time when debugging quality. Segment long scripts over 500 words into logical chunks. Add expressive tags like [sigh] and [laughter] where needed for emotional rendering.