DJ Toolkit
GitHub

Land every acapella on the one.

DJ Toolkit is a free app for DJ prep, on Windows and macOS. Mark four beats at the chorus, add a count-in, and the vocal comes in on the downbeat, first time.

Download, freeTry the four-beat lock

Free and open source · Windows 10 and 11, macOS 12 or later · Also turns your music folders into Spotify playlists

DJ Toolkit's Acapella prep page: a vocal waveform with four numbered beat markers at the chorus and the tempo locked at 124.00 BPM.DJ Toolkit's Acapella prep page: a vocal waveform with four numbered beat markers at the chorus and the tempo locked at 124.00 BPM.

Four beats lock the grid.

Acapellas have no drums, so tempo detectors guess. DJ Toolkit suggests four beats at the loudest part, loops them with a click, and you drag each one until the click sits on the beat.

Four careful beats set the tempo and the phase for the whole track. Try the idea here.

Space
plays the loop, with a click on the grid
B
taps beats along with the music
Drag the top strip
scratches back and forth, so you hear where you are
Half, Double
fix a tempo read at the wrong speed

124.0BPM

An example at 124 BPM: four beats of count-in, then the vocal.

Tap along with a song you know: the button, the space bar, or B as in the app. The grid locks on your fourth tap.

Then set the start.

Click the beat where the vocal comes in. It snaps to the grid, and the beats before it become the count-in: a click, silence, or your own sample.

Preview plays the count-in, then the vocal. Export saves a new file with the tempo in its name and in its tags, ready for rekordbox and the USB.

Saves as
Demo vocal - 124bpm.wav
Formats
WAV and FLAC at 24-bit, MP3 at 320 kbps
Remembers
The four beats and the start, for every file you've worked on
Step two in DJ Toolkit: the amber start marker on the first beat of the vocal, with the four-beat count-in before it.Step two in DJ Toolkit: the amber start marker on the first beat of the vocal, with the four-beat count-in before it.

Your folders, as Spotify playlists.

Point it at your music folder. Every folder inside becomes a private Spotify playlist, so you can dig on your phone and play from your drive.

On your driveOn Spotify
Music\HouseLocal: House
Music\DiscoLocal: Disco
Music\TechnoLocal: Techno
Music\AcapellasLocal: Acapellas
DJ Toolkit's Spotify sync page: the music folder, the playlist name, match strictness, and the Preview changes button.DJ Toolkit's Spotify sync page: the music folder, the playlist name, match strictness, and the Preview changes button.

Preview first. Nothing changes on Spotify until you choose Sync playlists, and that stays off until you've seen the preview.

Your music isn't touched. DJ Toolkit reads tags and file names, and nothing else.

Each track is searched once. Matches are remembered, so a big library fits inside Spotify's daily limit.

Short guides you can argue with.

One recommendation each, then two to four steps. Think one is wrong? Post a question or a challenge under it, anonymously.

Booth or Daylight.

Calm and dark for clubs and late-night prep. Bright and high-contrast for a laptop in the sun. This page switches too.

The Tutorials page in Booth, the dark look.
Booth
The Tutorials page in Daylight, the light look.
Daylight

Install it in a minute.

Download it, open it, prep. Version v0.1.3, free, with nothing else to install.

Windows 10 and 11

Download for Windows
  1. Unzip DJ-Toolkit-Windows.zip.
  2. Open the DJ Toolkit folder and double-click DJ Toolkit.
  3. If Windows says it protected your PC, choose More info, then Run anyway.

macOS 12 or later, Apple silicon

Download for macOS
  1. Open DJ-Toolkit-macOS.dmg and drag DJ Toolkit into Applications.
  2. Open DJ Toolkit from Applications.
  3. If macOS says it can't check the app, open System Settings, then Privacy & Security, and choose Open Anyway.

Why the warning? The app isn't signed with a paid certificate yet, and all of its code is on GitHub. Run it from source instead, if you'd rather.

Open source, and easy to work on.

MIT licence, Python and Qt. About 160 automated tests run in a minute, with no sound card and no network.

Working with an AI coding agent? AGENTS.md gives it the rules and the commands, and guardrail tests catch it when it breaks one: a hard-coded colour, a word the app doesn't use, a secret in a commit.

git clone https://github.com/tomgreef/dj-toolkit.git
cd dj-toolkit
py -3.12 -m venv .venv
.venv\Scripts\pip install -r requirements-dev.txt
check.bat

Early, and honest about it.

It's tested with generated audio and about 160 automated tests. It hasn't met many real acapellas or a live Spotify account yet.

If you play out, try it on your own music and say what felt off. No code needed.

Share DJ feedbackRead the user guide Ask or talk it through

Vote on what comes next.

Every idea is a GitHub issue, and a thumbs-up is a vote. Back the ones you want, suggest your own, or report a bug. The app's Requests page shows the same list.

  1. 0Detect the key of an acapella, and warn about a key clash
  2. 0Make an acapella from a full track (offline vocal separation)
  3. 0Stretch an acapella to the tempo of your set
  4. 0Carry the grid and cue points into rekordbox
  5. 0Prep a whole folder of acapellas in one go
  6. 0Show the tracks in your Spotify playlists that aren't on your drive
Suggest a featureReport a bugSee every idea

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