ToolsVideo & Audio

Private on-device speech AI

AI Voice Generator

Generate an original synthetic English voiceover with selectable voices and adjustable pacing on this device.

Free to use Your text and generated audio stay in this browser. The first run downloads a public AI runtime, model, and selected voice from their public hosts; those hosts receive an asset request, not the text you type.

Loading tool workspace…

How it works

Complete the job in three clear steps

  1. Enter up to 2,000 characters of English text and choose an American or British voice.
  2. Download the public Kokoro model, then synthesize the speech locally in this browser.
  3. Preview the generated audio and download the uncompressed WAV file.

Important

Check the result before relying on it

Keep an untouched copy of important source files. Browser processing depends on available device memory, and you should inspect every downloaded result before deleting the original.

Practical details

What this Lucaden tool does

Generate an original synthetic English voiceover with selectable voices and adjustable pacing on this device.

Lucaden uses the 82-million-parameter Kokoro text-to-speech model through a browser-only kokoro-js and Transformers.js runtime. Inference runs with WebAssembly and produces 24 kHz mono PCM audio.

The runtime and model revision are pinned and the runtime bundle is verified with SHA-256 before execution. Long input is divided into short segments and joined with small pauses so no sentence silently disappears at the model token limit.

Included capabilities

  • Multiple synthetic voices
  • Voice and accent selection
  • Speed controls
  • Private on-device inference

Useful for

  • Draft explainer voiceovers
  • Test script pacing
  • Create demo narration
  • Compare voice styles

Questions

About this tool

Is my text sent to an AI service?

No. Lucaden downloads the Kokoro browser runtime, quantized model, and selected voice files, then performs inference on this device. The typed text is not placed in those download URLs or uploaded by the tool.

Can the voice be used without review?

No. Listen for pronunciation, names, numbers, pacing, and artifacts. Clearly disclose synthetic speech where appropriate, and never use it to impersonate a person or mislead listeners.

Why is the first run large?

The pinned browser runtime is about 2.1 MB, the quantized English speech model is about 92 MB, and each selected voice is about 0.5 MB. Compatible browser caches can reuse downloaded assets on later visits.

Open-source foundations

Built transparently

Lucaden documents its standards sources, architectural references, and permissive runtime dependencies while keeping this workspace consistent with the Lucaden interface.