Hey dev community! I want to share a project I just launched: MasterDJ AI — a professional DJ platform that runs entirely in the browser.
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What is it?
A single HTML file (~400KB) that gives you a full DJ console. No frameworks, no dependencies, no server required for the core app.
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Tech Stack
Web Audio API — real-time audio processing (BufferSource, BiquadFilter, Convolver, Analyser nodes) #
Canvas API — rainbow waveform visualization colored by frequency #
ID3v2 parser — extracts album cover art from MP3 metadata in pure JavaScript #
Center channel cancellation — karaoke mode that removes vocals by subtracting R from L channel #
CSS custom properties — 8 theme skins switchable in real-time #
i18n — 13 languages with RTL support for Arabic and Hebrew #
PHP/MySQL — backend for license keys, song requests, and visitor tracking
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Key Features
- Dual deck mixing with independent volume, speed, pitch
- 3-band EQ with kill switches per deck
- 4 real-time effects: Filter, Delay, Reverb, Phaser
- Smart automix with 3-second ease-in-out crossfade
- BPM detection using energy-based onset analysis
- 8 hot cue pads and beat loops per deck
- Session recording via MediaRecorder API
- Live Song Requests — audience scans QR code to request songs in real-time
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The Song Request System
This is the feature I'm most proud of. The DJ opens a "room," gets a QR code. People at the party scan it with their phone — no app needed — type a song name, and it appears on the DJ's console in real-time via PHP polling.
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Try it
🔗 [https://masterdjai.com](https://masterdjai.com)
Free version available. Pro ($14.99 one-time) unlocks effects, karaoke, hot cues, and premium skins.
Would love to hear your feedback, especially on the Web Audio API implementation!