Browser TTS workspace

Supertonic TTS

Free Supertonic 3 text to speech across 31 languages and 10 built-in voices with local browser inference after download.

Private generation WAV + MP3 export 31 languages · Local
31
multilingual local TTS
languages
10
M1-M5 + F1-F5
built-in voices
~99M
public ONNX assets
params
WebGPU
+WASM fallback
GPU+CPU

TTS works best on desktop

Audio generation uses WebGPU/WASM. Desktop Chrome or Edge gives the most reliable result.

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About Supertonic TTS

Supertonic 3 is an on-device multilingual text-to-speech model from Supertone. This browser integration exposes all 31 officially supported languages, covering English, Japanese, Korean, Arabic, Hindi, Vietnamese, Indonesian, and a broad range of European languages.

The browser integration runs the public ONNX assets through ONNX Runtime Web. It loads separate duration predictor, text encoder, vector estimator, and vocoder models, then performs local denoising and waveform generation directly in the browser.

Supertonic uses language-tagged Unicode text rather than a server-side phonemization API, so synthesis stays local after the initial model and voice-style downloads. The asset base URL is configurable and defaults to Hugging Face, making it straightforward to move model delivery to a CDN or R2 later.

Compare engines: Kokoro TTS (54 voices · q4 or fp32) · Kitten TTS (8 voices · Lightest) · Piper TTS (25 voices · Fastest CPU)

Language Tags, Voices, and Denoising Steps

Supertonic accepts Unicode text together with an explicit language selection. The integration wraps the text in the corresponding language tag before inference, so choosing the matching language is part of the model input rather than a display-only filter. Its ten M1–M5 and F1–F5 choices are built-in style files; the labels indicate catalog categories and do not identify real speakers.

Denoising steps trade computation for another refinement pass, but more steps do not guarantee that every sentence sounds better. Begin around the interface default, compare a fixed sample, and increase steps only when the audible result justifies the extra time. Speed and steps interact with device performance, text length, punctuation, and backend, so retain those settings with an important export.

When Supertonic Is the Appropriate Engine

Choose Supertonic when its 31-language list includes the script language and you want a language-tagged local synthesis path after model assets load. Unlike non-English Kokoro, this integration does not send text to the OfflineTTS phonemization endpoint. It does download several ONNX and voice-style assets from the configured host, and normal website analytics remain separate network activity.

Supertonic is not automatically the best choice for every supported language. Compare pronunciation, script coverage, model load, generation time, and the available voice styles with the other engines. It does not clone a speaker, infer the language automatically for you, or verify that a translation is correct. Review the final audio and upstream terms before publication.

Getting Started with Supertonic TTS

1

Load the ONNX Models

Supertonic uses multiple ONNX assets for duration, text encoding, denoising, and vocoding. The first load downloads and caches the model files from the configured asset host.

2

Choose Language and Voice

Pick the language that matches your text, then choose one of ten built-in voices: M1-M5 or F1-F5.

3

Set Steps and Speed

Use 8 steps for a practical default. Higher step counts can improve quality but take longer. Speed around 0.9-1.5 is usually the useful range.

4

Generate and Export

Generate speech locally, preview it in the browser, then download WAV for editing or MP3 for sharing.

Tips for Supertonic TTS

1

Match the selected language to the input text. Supertonic wraps text in language tags before inference. Selecting the right language gives the model the best pronunciation context.

2

Start with eight denoising steps. Eight steps is the upstream browser demo default. Increase steps for quality checks and reduce them for faster drafts.

3

Use WebGPU when available. Chrome and Edge can run ONNX Runtime Web with WebGPU. The app falls back to WASM when WebGPU is unavailable.

4

Keep long passages structured. The tool chunks long text and inserts short pauses. Paragraphs and punctuation help preserve natural pacing.