Pay what you want · macOS & Windows · Runs offline
Your library already knows what to play next. Rekordbox just won't tell you.
Rekordbox stores your keys and your BPMs. It has no idea which of your eight thousand tracks actually belong next to each other. Track2Mix reads your collection, listens to every file on your own machine, and scores each track for energy — then hands you the shortlist that mixes.
Anonymised sample view — structure and columns are the real app.
The problem
You didn't buy 8,000 tracks so you could play the same 60.
Every DJ with a large library has the same failure mode. You know the top of your collection cold and the rest of it not at all. Rekordbox's own tools don't fix that: sorting by key gives you hundreds of technically-valid options with no sense of which ones hit the same, and sorting by BPM ignores key entirely. So you fall back on memory, and memory only holds the tracks you already played last month.
Key alone is too coarse
Six hundred tracks in 8A is not a shortlist. Harmonic compatibility tells you what can work, never what should.
Energy isn't a number you have
Rekordbox has no honest measure of how hard a track hits. So the set you build on paper collapses the moment you play it.
Your back catalogue is dead weight
Tracks you bought, tagged, and never opened again. The whole point of a library is that you can reach all of it.
How it works
Three steps, and you never leave your own hard drive.
Track2Mix doesn't ask you to upload your collection, sign in, or move your files. It reads the XML that Rekordbox already exports, decodes the audio sitting on your disk, and writes its findings to a single SQLite file next to it.
Export your collection
In Rekordbox: File → Export Collection in xml format. That file is the only thing Track2Mix needs to find your library.
Let it listen
Track2Mix decodes every track — MP3, FLAC, WAV, AIFF, M4A — and measures loudness, dynamics, brightness, spectral movement and rhythmic density, in parallel, across all your cores.
Dig, then export
Click any track to get its harmonically and rhythmically compatible neighbours, ranked. Tick the ones you want and export an M3U8 that Rekordbox imports directly.
# Prefer the shell? The analyzer is a standalone CLI. track2mix analyze --xml ~/rekordbox.xml --skip-analyzed track2mix top --by energy --genre liquid --limit 20 track2mix compat "the track you're opening with" --bpm-tol 3
Under the hood
It listens to the record, not the metadata.
Genre tags and star ratings describe what you thought about a track the day you filed it. Track2Mix ignores all of that and decodes the actual audio, because the only thing that reliably predicts whether two records sit together is what's in the waveform.
- Loudness and dynamic range. How hard it hits, and how much it breathes. A compressed roller and a track that swings between silence and full weight can average out the same — telling them apart is most of the job.
- Spectral brightness. Where the weight of the sound actually sits. This is what separates something dark and sub-heavy from something crisp and forward, long before you'd call it a genre.
- Spectral movement. How much the sound changes moment to moment. A track that evolves and a track that loops can share every other number and feel nothing alike in a mix.
- Rhythmic density. How busy the percussion is, independent of tempo. Two tracks at the same BPM can be miles apart on this, and it's usually what makes a transition feel rushed or flat.
Those signals are combined into one energy value per track, weighted so the result matches how a set actually feels rather than what a meter says. Getting that balance right is the part I've spent the most time on, and it's what the beta is for.
One track, four signals, one number
Then ranked against every harmonically compatible track in your library.
It doesn't grind through whole files
Decoding every second of every track would make a big library an overnight job. Track2Mix samples a handful of representative stretches across each record instead — enough to characterise it, at a fraction of the cost, across every core you have.
Energy is the tiebreaker, not the whole answer
Harmonic and tempo compatibility decide which tracks are eligible. Energy decides the order. That's the part Rekordbox can't do for you — turning six hundred technically-valid options into five worth auditioning.
Built to be corrected
The weighting is tuned by ear on real libraries, which means it can be wrong on yours. Every score is visible and sortable, so you can check it against tracks you know cold — and tell me where it's off.
What you get
Built for people with more tracks than they can remember.
Sort by energy
The same eight tracks, reordered by how hard they hit.
Alphabetical order tells you nothing about a set. Energy order tells you where each record belongs in one — and it is the same click either way.
- 1 Peak-time neuro 10
- 2 Warehouse banger 9
- 3 Rolling drums 7
- 4 Tech house groove 6
- 5 Liquid stepper 5
- 6 Deep roller 3
- 7 Dubby breakdown 2
- 8 Ambient opener 1
A real energy score
Every track gets a 0–10 energy value derived from its actual waveform — loudness, dynamic range, brightness, spectral movement and rhythmic density. Sort by it and your hardest tracks rise to the top.
Camelot-aware neighbours
Pick an anchor and Track2Mix returns same-key, ±1-on-the-wheel and relative major/minor matches inside your BPM tolerance. It reads Camelot, classical and open-key notation from your existing tags.
Offline by construction
No account, no upload, no telemetry. Your library never touches a server, because there is no server. Everything lives in one SQLite file you own and can delete.
Fast enough to actually run
Written in Rust and parallelised across every core, and it samples representative stretches of each record rather than grinding through whole files — enough to characterise a track at a fraction of the cost.
Round-trips into Rekordbox
Exports standard M3U8 playlists that Rekordbox imports without complaint. Track2Mix is a lens on your library, not a replacement for it — nothing to migrate, nothing to lose.
GUI and CLI, same engine
A desktop app for digging and a scriptable command-line analyzer for everything else. Both read the same database, so you can automate the boring parts.
No overclaiming
What Track2Mix does, and what it deliberately doesn't.
Plenty of tools in this space promise AI that builds your set for you. Track2Mix doesn't, because that isn't a solved problem and pretending otherwise wastes your time. Here is the actual scope, so you can decide in thirty seconds whether it's useful to you.
- Measures energy from the audio itself. Not from genre tags or guesswork — from loudness, dynamics, brightness, spectral flux and onset rate.
- Reads the keys you already trust. Track2Mix uses Rekordbox's own key analysis rather than second-guessing it, so your results match what's on your CDJs.
- Handles real, messy libraries. Moved drives can be remapped with a path map; Beatport streaming stubs and dead entries are reported instead of silently dropped.
- Does not detect key itself. If a track has no key in Rekordbox, Track2Mix has none either. Analyse in Rekordbox first.
- Does not write back to your Rekordbox collection. It exports playlists. Your collection file is never modified.
- Does not build the set for you. It narrows eight thousand tracks to a handful worth auditioning. The selection is still yours.
Get Track2Mix
Download it free. Pay what it's worth to you — or nothing at all.
There is no paywall, no trial timer and no locked features. If Track2Mix earns you a better set, tip what it's worth. If money's tight, take it free and don't think twice — that's not a loophole, it's the deal.
Get the build
macOS 11+ (Apple Silicon & Intel) and Windows 10+. Requires Rekordbox 6 or 7 for the collection export. Tell me who you are and the download link appears right here, and lands in your inbox.
Here it is — also on its way to your inbox.
Download Track2MixI'll email you the link and a note when a new version lands. Nothing else, never passed on, one click to leave. Track2Mix itself still runs entirely offline once installed.
Tip jar
Track2Mix has no investors and no ads. Tips are what decide whether Serato support, key detection and set-arc planning get built. Pay by PayPal in two taps — no account needed on my side, none created on yours.
Can't afford it right now? Then don't pay. Download it, use it for as long as you like, and tip later or never. Nothing is withheld and nobody gets chased.
Questions
The things people ask first.
Does this touch my Rekordbox collection?
No. Track2Mix only reads the XML file you export, and it only ever writes M3U8 playlists plus its own SQLite database. Your collection file and your audio files are never modified.
How long does analysis take?
It depends on your machine and your library, and it's parallelised across all your cores. Because Track2Mix samples representative stretches of each track rather than decoding whole files, it's dramatically cheaper than a full Rekordbox re-analysis. Use --dry-run first to see how many of your tracks actually resolve to files on disk before committing to a long run.
Why does it need keys from Rekordbox instead of detecting its own?
Because you already trust Rekordbox's keys and they're what show up on your CDJs. Adding a second, disagreeing key detector would create confusion rather than value. If a track is unanalysed in Rekordbox, analyse it there first.
Serato, Traktor, Engine DJ?
Not yet — Track2Mix reads the Rekordbox XML format today. The analysis engine is library-agnostic, so other sources are a matter of adding parsers. If you want one, say so in the signup form and it moves up the list.
Is it really free? What's the catch?
No catch on the money. Track2Mix is pay-what-you-want: the full app downloads free with nothing held back, and you tip only if it earns it. If you genuinely can't afford to pay, use it free — that's the intended path, not an exploit. The one thing I do ask for is your name and email before the download, because during beta I need to be able to tell you when something is fixed or broken. That's the whole reason, and the list is used for nothing else.
Why pay-what-you-want instead of a price?
Because I don't yet know what this is worth to you, and guessing wrong in either direction is expensive. A fixed price on an unproven tool filters out exactly the DJs whose feedback I need most. Tips tell me what people actually value, and they fund what gets built next. If Track2Mix becomes essential to enough people, a paid tier for heavier features makes sense later — what's free today stays free.
Does my music or data get uploaded anywhere?
No. There is no backend. Analysis runs locally, results are stored locally, and the app makes no network calls to run. The only things that reach me are the name and email you enter to get the download — they go to my mailing list and nowhere else, and you can leave in one click. Your library, your tracks and your analysis results never leave your machine.