# I built a complete DJ console in a single HTML file using Web Audio API

> Source: <https://dev.to/manichov1972/i-built-a-complete-dj-console-in-a-single-html-file-using-web-audio-api-dod>
> Published: 2026-08-29 01:38:28+00:00

Hey dev community! I want to share a project I just launched: **MasterDJ AI** — a professional DJ platform that runs entirely in the browser.

##
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.

##
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
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**CSS custom properties** — 8 theme skins switchable in real-time
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**i18n** — 13 languages with RTL support for Arabic and Hebrew
-
**PHP/MySQL** — backend for license keys, song requests, and visitor tracking

##
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

##
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.

##
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!