Slicerex

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Browser-based audio phrase splitter. Upload an audio file, automatically detect phrases using silence detection, edit the results, and export individual phrases as MP3 files. Everything runs client-side — no server required.

Built to prepare audio tracks for Repeit — a tool for language learning through spaced repetition of audio phrases.

Features

• Silence-based phrase detection — configurable threshold, minimum silence/phrase duration, and padding
• Interactive waveform — visualize audio with draggable phrase boundaries (WaveSurfer.js)
• Phrase editing — merge adjacent phrases, split phrases at midpoint, exclude phrases from export
• Playback — play individual phrases, play next in sequence
• MP3 export — export non-excluded phrases as numbered MP3 files via a Web Worker (lamejs)
• Works offline — PWA with service worker caching

Usage

1. Upload an audio file (any format supported by Web Audio API)
2. Adjust detection settings if needed (silence threshold, durations, padding)
3. Click Detect phrases
4. Review and edit results — drag boundaries on the waveform, merge/split/exclude phrases
5. Click Export to download each phrase as a numbered MP3 file

Development

npm run dev          # Start dev server
npm run build        # TypeScript check + production build
npm run test         # Run tests
npm run lint         # Lint
npm run format       # Format code

Tech Stack

React 19, TypeScript, Vite, Tailwind CSS 4, WaveSurfer.js 7, lamejs, Vitest