In DJing, stems are the separate parts of a track, usually vocals, drums, bass and melody, that you can mute, solo or swap one by one. Most DJ apps now make them for you: they split the finished track while it plays. Short version: they are great for dropping an acapella (a vocal on its own) over another track and for cleaner mix-outs, they do not replace mixing skills, and the quality depends on the track more than on the app. Apps differ on live versus prepared, price, and what your computer can handle.
What a stem is
A stem is one layer of a mix. The producer has the vocals, drums, bass and the rest as separate files; your DJ app does not, so it rebuilds them from the finished stereo track. Most apps give you four parts: vocals, drums, bass and a fourth bucket called melody, instruments or "other" that holds everything else (synths, guitars, effects). rekordbox started with three parts (vocal, drums, inst) and added a four-stem mode with a separate bass in version 7.2.8.
How the separation is done
The engine is a neural network trained on multitrack recordings where the real parts are known. It learned what a voice, a kick or a bassline looks like inside a mix, and it estimates them in a track it has never heard. It runs on your own machine, not in the cloud. Serato and Traktor use the processor, and Traktor's engine comes from iZotope's RX audio repair software. VirtualDJ can use your graphics card. djay runs Neural Mix on the Neural Engine in Apple chips. Engine DJ renders the stems in its desktop app with zplane's STEMS PRO engine, and the standalone player only plays the result.
Who does what
| App | Feature name | Live or prepared | Included in |
|---|---|---|---|
| Serato DJ Pro | Serato Stems | Live, optional prepare crate | Serato DJ Pro and Serato DJ Lite, no extra cost |
| Traktor Pro 4 | Stem Separation | Prepared, one track at a time | Traktor Pro 4 |
| VirtualDJ 2026 | Stems 2.0 | Live, Fast mode for older computers | Pro license (Business includes Pro) |
| rekordbox 7 | STEMS (Track Separation) | Live, in Performance mode | All plans, including Free |
| djay Pro 5 | Neural Mix | Live | PRO subscription; some controllers unlock it |
| Engine DJ 5 | Stems | Rendered on the desktop, played on the hardware | Free on PRIME 4+ and PRIME 4 G2, one-time license on other players |
| Mixxx 2.6 beta | Stem file support | Plays files prepared with other tools | Free, open source |
Checked October 2026.
Serato DJ Pro brought Serato Stems in version 3.0 in 2022: four stems on pads, Acapella and Instrumental buttons, and pad FX such as echo and brake on one part. The Stems Prepare crate analyzes tracks in advance to spare your processor. Serato DJ Lite has the pads and the two buttons, without the stem FX.
Traktor Pro 4 calls it Stem Separation and is the one desktop app that does not work live: you generate the stems before you play the track, one track at a time, and reviewers measured about a minute and a half for a three-minute track. Native Instruments says it chose quality over speed.
VirtualDJ has had live stems since 2020; Stems 2.0 splits a track into vocals and an instrumental, then into drums, bass, hi-hat and melody. It comes with the Pro license.
rekordbox 7 calls it STEMS or Track Separation. It runs live in Performance mode (the mixing mode, not the USB export mode) and is in every plan, including Free.
djay Pro calls it Neural Mix. It runs live on Mac, iPhone, iPad and Windows and needs the PRO subscription, though some controllers unlock it.
Engine DJ added Stems in version 4.2 in November 2024. You render tracks or playlists in Engine DJ Desktop, copy them to your drive, and the player gets a Stems pad mode plus Acapella and Instrumental buttons. Rendering is free. Playback is free on the Denon DJ PRIME 4+ and PRIME 4 G2 and needs a one-time $9.99 license on the other Denon DJ and Numark players (PRIME GO, SC LIVE, PRIME 2 and 4, SC6000, Mixstream Pro and more).
Mixxx does not separate anything yet. The 2.6 beta plays stem files made with other tools, in the Native Instruments stem format, with volume and effects per stem. The stable release is still 2.5.
Players, controllers and your laptop
No AlphaTheta player separates stems on its own: the CDJ-3000X, XDJ-AZ and OPUS-QUAD play your USB tracks as they are. Plug a CDJ-3000X or an XDJ-AZ into a laptop running Serato DJ Pro, though, and the hot cue buttons or pads switch to Serato Stems control. On controllers, look for dedicated buttons: the DDJ-FLX10 (Track Separation buttons for rekordbox and Serato), the DDJ-REV5 (Stems mute, solo and separate), the Rane Four (a Stems pad mode and a Stem-Split across two decks) and the Traktor Kontrol S4 MK3 and X1 MK3. Other controllers work too, through a pad mode.
Live separation is heavy. Serato's recommended spec is a 2017 or newer computer with a dual-core Intel i5 or Apple silicon and 8 GB of RAM; below that, Serato tells you to prepare stems ahead or raise the buffer size (the small delay your audio interface uses to avoid dropouts). VirtualDJ recommends an Nvidia GTX 1050 with 4 GB of video memory or an AMD Radeon RX 5600 XT or better, runs well on Apple silicon, and has a Fast mode for older hardware. Rule of thumb: Apple silicon or a recent laptop with a real graphics card is fine; anything older should prepare stems before the gig.
What stems are good for
- An acapella over another track. Pull the vocal from track A and lay it over the instrumental of track B in the same key and tempo.
- A breakdown on demand. Mute the drums for 16 bars and bring them back on the one. The crowd hears an edit; you pressed one pad.
- Avoiding a vocal clash. Two singers at once is the classic mistake; kill one during the overlap.
- Quick mashups. Drums from one record, bass and melody from another. Sketch it live, build it properly at home if it worked.
- Cleaner mix-outs. Fade the bass of the outgoing track rather than the whole track, so two basses never fight.
- Practice. Solo the drums to hear where phrases start, or the bass to train your ear for keys.
Where it falls apart
Quality depends on the track more than the app. A clean, modern, dry mix separates well. A dense track with layered synths, or an old recording with tape hiss and room sound, comes out watery. Reverb and delay tails are the worst: the model cuts them off or leaves them in the wrong stem, so a "vocal" from a big-room track drags half the pad along. Vocals bleed into the "other" bucket and back, a ghost voice when you mute the vocal. Latency is the next catch: on an older laptop the first seconds after you press a stem pad can glitch; preparing stems beforehand fixes it. Streamed tracks are often excluded: Serato, rekordbox and djay Pro all turn stems off for Spotify and Apple Music tracks.
Three rules so it stays musical
- Use it where the music has a reason. One acapella moment an hour hits harder than ten. If you cannot say why the vocal belongs there, do not add it.
- Match key and phrase first. A stem does not fix a key clash or a vocal that starts mid-bar. Line up phrases and key, then press the pad.
- Prefer muting to soloing. Removing one part is almost always cleaner than isolating one, because the artifacts hide under the rest of the music.
The rights side
Making an acapella in your DJ app for your own set is generally treated like playing the track. Recording a mashup and releasing it, even as a free download, is a different thing: it usually needs permission from the rights holders of every track in it. The rules differ by country and none of this is legal advice. Your local collecting society (the body that collects music royalties in your country) is the place to ask.
Quick answers
Which DJ software has free stems? rekordbox lists STEMS on every plan, Free included, and Serato DJ Lite has Serato Stems at no cost. Engine DJ renders stems for free, and playback is free on the PRIME 4+ and PRIME 4 G2. Mixxx is free but only plays stem files made elsewhere. VirtualDJ, djay and Traktor put stems on the paid side. Free DJ software has the rest of each free tier.
Do I need stems to DJ? No. Every classic transition, from a long blend to a quick cut, works with EQs and faders. Stems add options; they do not replace the basics.
Can I download the stems of a track? Sometimes. Artists and labels release official acapellas, instrumentals or stem packs, often for remix contests, and the Native Instruments stem format packs four parts into one file. For everything else, your DJ app makes them.
Do stems work with streaming? Often not. Serato, rekordbox and djay Pro turn stems off for Spotify and Apple Music tracks, so use files you own for anything you plan to split.
Stems are a tool, not a style. Pick the app that fits your gear first (our DJ software comparison covers price, platforms and streaming), then build the crate: every style on Digger Digger lists the tracks the big DJs really play, and the crate button saves them for your next acapella experiment.