Browser 108

max 1GB

Inspector audio/dj-booth

DJ Booth

Overview

The DJ Booth is a two-deck DJ workstation that runs in your browser. Every track is measured when it loads — tempo, beat grid, Camelot key and loudness — with the same analysis as the platform's BPM, key and loudness tools, and the beat grid is refined further so that sync stays within a millisecond. The decks run inside the audio engine itself, so loops, hot cues and sync land on the sample. A three-band isolator, a bipolar filter and three effects per deck feed a crossfader and a master limiter that keeps the output from clipping, and the recorder writes the set to a WAV file with a cue sheet of when each track came in.

Practise a set anywhereMix on a laptop with no DJ software installed, and hear exactly how two tracks sit together.
Plan harmonic transitionsThe library shows which tracks share a compatible key and a reachable tempo with what is playing.
Record a mix with its tracklistRecord the set and keep a .cue file and tracklist with the time each track came in, ready to publish alongside it.
Check a promo before you buy itLoad it next to a track you know and see whether its tempo and key will work in your sets.

Key features

Two decks with the BPM, beat grid, Camelot key and loudness measured on load
Sync to the other deck's tempo and beat, including half and double time
Key lock: change the tempo without changing the key
CDJ-style cue, eight hot cues per deck, beat loops from 1/4 to 32 beats and loop roll
Three-band isolator EQ with kills, a bipolar filter, echo, reverb and filter sweep
Loudness auto-gain, a crossfader with three curves and a master limiter that never clips
Headphone cue on a four-channel interface, as split cue, or on a second output
Record the master to WAV, with a .cue file and tracklist of when each track came in
Library with harmonic and tempo hints; cues and analysis remembered in this browser
Keyboard shortcuts and MIDI learn

Set

Audio Tools 14

Neighbours

01 Audio Transcriber 02 Audio Converter 03 BPM Detector 04 Extract Audio from Video 05 Audio HLS Stream Generator 06 Key & Camelot Finder

Specification

Command: audio.dj_booth
Set: Audio
Input: MIXED
Output: MIXED
Max file: 1GB
Batch: yes

MPEG WAV FLAC MP4 OGG OPUS AAC WEBM

Runtime

Engine: ffmpeg-wasm 0.12
Threads: — workers
Isolated: —
WebGPU: —
Memory: —

Transport 0 B

The file is opened, worked on and written back inside this tab. No upload step exists in this tool — there is nowhere for the bytes to go.

Keys

Search: ⌘K
Panels: ⌘1 · ⌘2
Full width: F
All keys: ⌘/

How it works

Drop your tracks

Audio files, or videos with an audio track. The first two go onto the decks, the rest into the library. Each deck plays as soon as its track is decoded.

Read the measurements

The same analysis as the BPM Detector, Key Finder and LUFS Meter runs on every track: tempo and beat grid, Camelot key, integrated loudness. The grid is then refined to about a millisecond for syncing.

Mix

Sync, cue in the headphones, ride the EQ and the crossfader, loop and drop hot cues. The playheads run in the audio thread, so loops and sync stay exact.

Record the set

The recorder writes what leaves the master to a WAV file as it plays, and notes when each track came in, for a .cue file and a tracklist.

Frequently asked

Are my tracks uploaded?

No. Files are decoded, analysed and played by your browser on your device. Cue points and analysis results are kept in this browser's own storage; the audio itself is only stored there if you switch that on for a track, and you see how much space it takes.

How does sync work?

Each track's tempo and beat grid are measured when it loads, and the grid's phase is refined to about a millisecond. Sync sets the follower's tempo to the leader's — at half or double time when that is the musical match, such as 85 and 170 BPM — then lines up the beats and keeps them lined up from inside the audio engine. A track with no steady tempo can't be synced; tap its tempo to give it one.

Does key lock change the sound?

Key lock uses a time-stretcher to hold the pitch while the tempo changes. Within ±8 % the pitch stays within a few cents of the original. It adds about 70 milliseconds of delay to that deck, so a jump you trigger on a key-locked deck is heard that much later.

How do I hear the next track in my headphones?

Press a deck's Cue button in the mixer. With a four-channel audio interface the headphones get outputs 3 and 4. With ordinary stereo output the DJ Booth can split the signal: the room in mono on the left, the headphones on the right. Some browsers can also send the headphones to a second output device; that adds latency.

Can I load a two-hour mix?

Yes, if the browser can play its format. Files longer than 30 minutes (15 on devices with 4 GB of memory or less) stream from the file instead of being held in memory. In that mode loops and hot cues work by seeking, sync matches the tempo but the beat only to about 20 milliseconds, and the tempo and key come from the first 10 minutes.

What does the recording contain?

Exactly what leaves the master, after the limiter, as a 16-bit WAV written to your browser's private storage while you play, so a long set doesn't fill memory. You can also save a compressed copy where the browser supports it, a .cue file and a plain-text tracklist.

Can I use a MIDI controller?

In browsers with Web MIDI (Chrome and Edge, for example), switch on MIDI, press Learn next to a control and move a knob, fader or button on your controller. The mapping is remembered in this browser.

Keys

Search: ⌘K
Panels: ⌘1 · ⌘2
Full width: F
All keys: ⌘/

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