How to use CortexDJ

Your first set in three choices and one button, the full console when you want it, and everything in between: the decks, collections, export to your DJ app, controllers, recording and streaming.

Written for CortexDJ 2.38.4 (November 8, 2026), on Windows and in the macOS beta.

1:30 · watch the workflow

The whole workflow in 90 seconds, in real footage. It was recorded with an earlier version, so the window looks different from 2.34 (the still above is 2.34 in Simple mode); the steps are the same. Nothing loads from YouTube until you press play; then the video plays from youtube-nocookie.com.

1. Install & first launch

1. Download the installer and run it. The installer is code-signed. Windows may still show a SmartScreen notice for a brand-new release: click More info → Run anyway; it is not a finding about the file.
2. On a Mac: unzip the download and drag CortexDJ.app into your Applications folder, then open it from there. Run it from Applications, not from Downloads, so updates replace the copy you use.
3. Your first set builds with no key at all: install it, point it at a folder and listen. Every set after that needs a key.
4. The key is free. In the app: Get a free key → type your e-mail → click the link in the e-mail or type its 6-digit code → done; CortexDJ activates itself (version 2.32 and later, on Windows and Mac). Or leave your email on the download page; it usually arrives within a minute, and you paste it under Settings → About → Activate. If your browser blocks the anti-spam check, we email you a confirmation link first. Nothing is sent unless you ask for it. Every key, free or Pro, works on up to 2 of your computers.
5. CortexDJ checks cortexdj.com for updates each time it starts and offers to install them: it installs the new version and reopens itself, on Windows and, since 2.35, on macOS too. If a Mac copy can’t update itself, it shows the new build in Finder with the steps. Your music is analyzed on your own machine and is never uploaded. The app contacts cortexdj.com only to activate your key, renew Pro, check for updates, request a free key when you ask for one (it sends the e-mail you type) and, if they’re switched on, send diagnostics (on by default up to version 2.31, opt-in from 2.32); the privacy policy lists exactly what.

2. Simple mode and Advanced mode

At the top of the window, next to the CortexDJ name, is a switch: SIMPLE | ADVANCED. The same choice is in the View menu. Advanced is the default, so an update never moves your controls; Simple is there for when you just want a mix.

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In Simple mode, one Make a mix card takes the place of the library, under the decks:

No music yet? The card shows Choose my music folder; later, Add music… analyses another folder (you can also drag one onto the window).

What Simple mode changes, and what it leaves alone

• Safe defaults, without touching your settings: Creativity Balanced (unless you picked a level in Settings yourself) and Safe buffering on. Switch back to Advanced and your own settings apply again.
• Hidden, not removed: the library browser, the RENDER SET button (the card’s button takes over), the beat view over both decks, the EQ knobs, each deck’s FX, loop and pad rows and its LOAD button, and the MIDI and Broadcast pages of Settings. The decks stay on screen and keep playing, a connected controller keeps working, and you can still drag a file onto a deck.
• Nothing changes the sound out of sight: when you switch to Simple, any EQ, filter, effect or loop it hides is put back to neutral first (not while an auto-mix is running, because the AI owns those controls then).
• Switch back to Advanced and every control is where you left it.

3. The two ways to mix

CortexDJ is both an AI auto-mixer and a pair of live decks. Pick whichever fits the moment; they share the same analyzed library.

• AI set: point it at a folder, choose a length and a vibe, and it selects, orders, beatmatches and mixes a full set for you. Great for a mix to upload or stream (with music you have the rights to), background music at home, prep, or just hearing your library mixed.
• Live decks: two decks you play by hand or with a controller: cue, beat-sync, keylock, EQ, filter, effects, hot cues and loops.

4. Build your first AI set

In Simple mode, the card above is the whole job. In Advanced mode:

5. Render vs Perform

In Perform you can grab any control at any time (nudge a deck, ride an EQ, drop a loop) and hand it back to the AI with ↩AI. Everything the AI does is shown on the decks, so you can see every move.

6. Blend length, transitions & Creativity

Blend length and transitions

Settings → Mixing → Blend length is where every transition starts, in beats (4 beats = 1 bar). It goes from 32 to 256 beats in whole bars, and the default is 128 beats (32 bars), about a minute at 128 BPM. It is saved and used for every AI set, rendered or live. The AI still fits each blend to the two tracks, using about half of it when the next track opens with vocals. The live auto-mix blends for at least 48 beats (12 bars), unless you set the length shorter on purpose, down to 32 beats (8 bars) for tight mixes.

You don’t have to open Settings for it: the set dialog and Simple mode both offer Short (32 beats), Medium (64) and Long (128), and whatever you pick there becomes the Blend length.

Creativity

Settings → Mixing → Creativity sets how bold and frequent the AI’s moves are, both live on the decks (Perform) and in a rendered file:

The moves ride filters, echo and the master bus, never the beat grid. You’ll hear filter-into-the-drop sweeps, echo throws, real double-drops and a mid-blend breakdown, and never a hard mute. Simple mode’s mixes use Balanced unless you pick a level here yourself.

Settings → Mixing → Rolls and slams is off by default. Turn it on to add beats that repeat faster and faster, tape stops and a short dip just before the new track lands. They are effects, but they can sound like playback faults.

7. The live decks

Load a track to a deck (double-click it in the library, drag it, or use the LOAD button), then mix by hand.

Modern or vintage

Since 2.34 each deck shows a progress ring by default: the time left in the middle, the time played as the arc and, while the auto-mix runs, a purple mark where its next transition starts, with MIX IN counting down to it. Under each waveform, one line reads elapsed, remaining and total time, BPM, key and the next transition countdown. Drag around the ring to nudge the track, as you would a platter.

Prefer the spinning turntable and tonearm? Settings → Mixing → Deck style → Vintage. It switches as soon as you press OK.

The controls

• Play / Cue: start, stop, and set a temporary cue point.
• Sync: beat-match this deck to the other: it matches tempo, locks the bar “one,” and holds the lock through the blend.
• Keylock (KEY): change tempo without changing pitch, so a sped-up track doesn’t sound chipmunky.
• 3-band EQ + filter: low, mid and high knobs in the mixer plus one filter knob per deck (left = low-pass, right = high-pass), the classic move for swapping basslines cleanly.
• Effects: flanger, echo and cut, one button each.
• Ring or platter: drag to nudge the beat. It’s a nudge surface, not a scratch surface: there’s no scratching in CortexDJ.
• Hot cues & loops: 8 hot-cue pads per deck (they survive restarts) and beat-locked loops.
• Crossfader, channel faders and master: blend the two decks and set the overall level.
• LOUD, COMP and LIMIT: the three master stages next to the master fader (loudness match, compressor, and limiter with true-peak protection), each with a meter. Click one to switch it off or on. All three are on by default; the limiter is always on when CortexDJ starts, and while it is off a CLIP light shows overs. Rendered sets always keep the limiter.

8. Library, collections & mashups

Collections

The left side of the library is the Collections sidebar:

• All tracks: the whole library.
• Crates: your own lists. Make one with New crate… (or the ＋ menu), then drag tracks onto it or right-click selected rows → Add to crate. Every selected row goes in, and dragging carries every selected track.
• Genres: collections built automatically from your tracks’ genre tags. Spellings like “Afro House”, “afro house” and “Afro-House” land in one collection.
• Music folders: only the folders you’ve opened, not every drive on your computer. Double-click one to analyse it again; ＋ → Add a music folder… adds another. Need the full tree? Tick Show all folders.

Pick a collection and the track list shows just those tracks. Press Mix this collection (or right-click it) and RENDER SET builds the set from them. The search box matches titles, artists, keys and BPM, and genres too: type “afro” and the sidebar narrows to Afro House.

Where each value came from

Hover a KEY, E (energy) or BPM value in the library to see its source: from Mixed In Key, from the file’s tag, or detected by CortexDJ. CortexDJ reads the key, BPM and energy tags that Mixed In Key, Beatport and other tools write into your files, on Windows and Mac. On Windows it also reads the results stored in Mixed In Key’s own library, read-only. For BPM, a tag or Mixed In Key only picks the tempo level (128 rather than 64); the beat grid is always CortexDJ’s own.

Everything else in the library

• Analyzed tracks, crates and cue points persist between sessions. Sort by key, BPM or energy, drag to reorder by hand, and delete straight from the list.
• Tracks you’ve already played this session are marked, so you can see at a glance what’s been used. Inside a single generated set every track is picked once; across a long multi-set night the marks keep you from doubling back.
• Mashups: load a track and the MASH column scores every other track 0–100 for how well it layers. Sort to find the best partners, or press Mashups to scan the whole library, and build a vocal-over-instrumental mashup, beatmatched and in key.

9. Export to rekordbox, Serato & more

Export is free on every tier and never rewrites your audio files. There are two ways in:

• Every rendered mix gets a folder next to it, named after the mix with “playlists” on the end. It holds the set in its play order: two rekordbox XML files (one playlist only, one with grids and cues), an M3U8 and an M3U, a Serato crate, and a README with the steps for each app.
• The library’s Export to rekordbox / Serato menu: Export whole library, Export SELECTED tracks, and Export the last AI set in play order, which works for a live auto-mix too. The whole library is also under File → Export library (Ctrl+E) and on the library’s right-click menu.

Mix plan: every set export also writes “<set> - mix plan.txt”: the running order with BPM and key, where each blend starts (MIX IN) and where the outgoing track starts to leave (MIX OUT), the transition length and the tempo change, so you can play the set yourself in rekordbox the way CortexDJ planned it. In Export the last AI set you can also tick Add mix points as memory cues (XML with grids and cues only): rekordbox then shows the planned MIX IN and MIX OUT points as memory cues. Memory cues belong to the track, so they show in every playlist that contains it.

• rekordbox
• Serato
• VirtualDJ
• Traktor
• Engine DJ
• Mixxx
• djay

rekordbox asks first

Before a rekordbox export from the menu, CortexDJ asks whether the tracks are already in your rekordbox collection, with beat grids and hot cues you set up there.

Yes: playlist only is the default and leaves your rekordbox beat grids and hot cues alone. No: with grids and cues also brings CortexDJ’s hot cues (A–H), key and BPM; on tracks rekordbox already has, they can replace the ones you set there.

Into each app

• rekordbox: the simplest way is the M3U8: File → Import → Import Playlist, pick “<set>.m3u8” and click Open. The set appears under Playlists in CortexDJ’s order, and tracks already in your collection keep their beat grids and hot cues. To use an XML file instead: in Preferences → View → Layout, tick “rekordbox xml” under Media Browser, and in Preferences → Advanced → Database, set “Imported Library” under rekordbox xml to the XML file. Then select rekordbox xml in the Media Browser, double-click “rekordbox xml”, then “Playlists”, then the “CortexDJ” folder in the tree view, and drag the set into your own playlists. For a set you export later, press the refresh button of the rekordbox xml view.
• Serato DJ: drag the M3U8 onto Serato’s crate panel, or copy the .crate file into the _Serato_/Subcrates folder of the drive your music lives on, then restart Serato. Serato keeps hot cues inside the audio files, and CortexDJ will not rewrite your music to put them there, so Serato gets the playlist only.
• VirtualDJ: drag the M3U onto a folder in the browser, or copy it into the VirtualDJ/Playlists folder in your Documents.
• Mixxx: Playlists → right-click → Import Playlist, and pick the M3U8.
• Traktor, Engine DJ, djay and other apps: import the M3U8 as a playlist, or the M3U if the app only accepts that extension.

App names are trademarks of their owners; CortexDJ is not affiliated with them. The README in each export folder has these steps with the exact file names.

10. MIDI controllers Pro

Plug in a supported controller before you start CortexDJ and it is detected at launch and mapped automatically. Plugged it in later? Open Settings → MIDI, press Rescan, pick it and press Connect.

• Pioneer / AlphaTheta, mapped from the maker’s MIDI chart: DDJ-FLX4, 400, REV1, FLX6, 1000, FLX10, and FLX2 (its LOAD buttons aren’t mapped)
• Hercules, mapped from the maker’s chart: DJControl Inpulse 300
• Community-derived maps (not tested on the hardware by us, so check each control after plugging in): Hercules DJControl Inpulse 200, Numark Mixtrack Pro FX, Mixtrack Platinum FX and Party Mix II

Any other class-compliant controller works via MIDI-learn: open Settings → MIDI, click a control in the app, then move the knob or button on your gear. You can import and export your mapping to share it, and reset to a controller’s factory map at any time. A controller keeps working in Simple mode; the MIDI page of Settings is in Advanced mode.

11. Safe buffering & a steady live sound

Settings → Audio → Safe buffering uses a slightly higher audio latency for steadier playback. It helps most while recording or streaming, and on busy computers.

• On by default on Macs with 8 GB of RAM or less, and always on in Simple mode. Elsewhere it stays off unless you turn it on.
• It switches itself on if the audio keeps stuttering (repeated dropouts while a deck plays), but never mid-song: it waits until both decks have stopped, then applies it, says so in the status bar and saves it.
• Under strain, CortexDJ eases off: while the audio is struggling, background analysis pauses and the live auto-mix keeps its transitions to plain blends, without creative moves, until the computer recovers.
• True-peak protection: a true-peak stage after the limiter, set to a −1 dBTP ceiling, catches the inter-sample peaks on the live output.
• A late next track no longer means silence: if the next track isn’t ready at the mix-out, the outgoing track loops its last bars until it is, the blend fits the time that’s left, and a track that won’t load is skipped instead of ending the set.

Output device, output mode and buffering are locked while a recording or stream runs, because changing them restarts the audio stream.

12. Recording & streaming Pro

• Record your set to an audio file, or capture HD video of the decks.
• Live-stream straight to YouTube, Twitch, Facebook or a custom RTMP server: paste your stream key in Settings → Broadcast (in Advanced mode).
• Audio is tapped straight from CortexDJ’s own engine, so system notification sounds and other apps never enter the recording or the stream. Video is rendered by the app itself (the Broadcast Scene), so the picture doesn’t depend on the window being visible: minimize it or cover it, and other windows or pop-up notifications never enter the frame. Only if the scene can’t start does CortexDJ fall back to capturing the screen, and it warns you on screen when that happens. On macOS that fallback captures the whole display, so close anything private before you go live.

Streaming notes: the music rights

CortexDJ gives you the tools, not the music licences. Whatever software mixed it, a set of commercial tracks can be muted, blocked or taken down:

• YouTube scans live streams for third-party content and may replace the stream with a placeholder image or interrupt it; this can happen even with a licence unless the rights owner has allowlisted your channel (YouTube Help).
• Facebook says content with music may be blocked, muted or removed if the music use isn’t authorized, and its ban on creating a music listening experience includes live videos (Meta Music Guidelines).
• Mixcloud describes itself as licensed with major rights holders, labels, publishers and collecting societies; uploads follow its rules, for example no more than 4 tracks by one artist for a show to be open to every listener (Mixcloud Help). Going live on Mixcloud needs a Mixcloud Pro subscription and RTMP streaming software (Mixcloud Live).
• Twitch runs a DJ Program for opted-in DJs: live streams only, tracks from its label-approved catalog only, with a music-cost deduction from earnings (Twitch DJ Program terms).
• Or mix music you have the rights to: your own productions, or tracks whose licence allows it. Read each licence; some royalty-free libraries forbid listen-only mixes.

Platform rules checked October 14, 2026. They change; read the platform’s own terms before you go live.

Free stays free: the AI mix still plays live and still renders to a file. Recording, video, streaming and MIDI control are the Pro features.

13. Keyboard shortcuts

On a Mac, use ⌘ where this table says Ctrl.

14. Free vs Pro

Pro is $7.45/month or $59/year; Lifetime is $127 once. See pricing.

15. Troubleshooting

• SmartScreen on install: click More info → Run anyway. The installer is code-signed; the warning can appear for a brand-new release and does not mean anything was found in it. If you would rather check the file yourself, open updates/latest.json: download the file its url names, then compare Get-FileHash <file> in PowerShell against the sha256 beside it.
• Crackles or dropouts: turn on Settings → Audio → Safe buffering, or switch to Simple mode, where it is always on. CortexDJ also turns it on by itself after repeated dropouts, once the music has stopped.
• No sound: check the output device in Settings → Audio; make sure the crossfader isn’t all the way to a silent deck and the master isn’t at zero.
• First analysis is slow: a large folder takes a while the first time (key, BPM, energy and structure for every track). Results are kept, so the same tracks don’t need the full analysis again.
• A set came out shorter than expected: look at the MIX column. Tracks marked ✕ are left out of automatic sets; CortexDJ asks before that makes a set much shorter than you asked for.
• Your grids or hot cues changed in rekordbox: export again and choose playlist only, so rekordbox keeps the ones you set there.
• Controller not detected: open Settings → MIDI, press Rescan, pick it and press Connect (or restart CortexDJ with it plugged in). Some units need to be switched to “computer/MIDI mode” on the device itself; then use MIDI-learn if it isn’t auto-mapped.
• Didn’t get your license email: check Spam/Promotions; if you were sent a confirmation link instead, open it to get the key. Still nothing? Contact hello@cortexdj.com, or ask on the community board.

New features ship often: see the changelog for what’s new, and the community board for ideas, bugs and help.