Mixed In Key is the industry standard and the team that invented Camelot notation. SignalKey is the free, browser-based alternative — same Camelot codes, no install, no annual licence, library export to Rekordbox, Serato and Engine DJ.
No spin — what each tool actually does and where the lines are drawn.
Free, browser-based key + BPM + Camelot detection. Drop a folder, get a CSV ready to import into Rekordbox or Serato. No install, no signup, no licence. Tool pages stay ad-free; only the long-form learning pages (glossary, charts, song database) carry a single quiet 'Sponsored' unit. Free uses sane daily caps to keep the GPU bill bounded.
Desktop app ($58 one-time) that's been the DJ-industry standard for over a decade. Camelot Wheel was their invention. Cue point detection, energy levels and library prep with Rekordbox + Serato + Traktor + Engine DJ + djay Pro support.
Mixed In Key is a one-time purchase, not a subscription. SignalKey tools are free with daily caps; Studio at $19/mo unlocks the workbench, 24-bit WAV stems and the API.
What each tool does, what it doesn't, and where the gaps are honest.
| Feature | SignalKey | Mixed In Key |
|---|---|---|
| Key detection accuracyMixed In Key has a slight edge on edge-case material thanks to a longer training history. | 88% first pass | ~88-92% first pass |
| Camelot Wheel notation | ||
| BPM detection | ±0.5 BPM | ±0.5 BPM |
| Half / double-time alternates | ||
| Mode (major/minor) |
| Feature | SignalKey | Mixed In Key |
|---|---|---|
| Browser-based — no install | ||
| Desktop app | ||
| Batch folder upload | ||
| Library tagging — auto-write to fileMixed In Key writes Camelot tags into ID3 / metadata. SignalKey exports a CSV that Rekordbox / Serato batch-imports. | ||
| Cue point detection | ||
| Energy level (1-10)SignalKey returns a 0-100 energy score; Mixed In Key uses the canonical 1-10 DJ scale. |
| Feature | SignalKey | Mixed In Key |
|---|---|---|
| Stem separation | ||
| Audio → MIDI | ||
| Chord detection | ||
| LUFS / mastering checks | ||
| Live tools (tuner, metronome) |
| Feature | SignalKey | Mixed In Key |
|---|---|---|
| Free tier | ||
| One-time fee | $58 | |
| Subscription | Free with caps · $19/mo Studio | |
| Trial | Free is the product | Demo with limited features |
Both tools are good. The right answer depends on what you're actually doing.
If you're already paying — here's the cleanest way to switch without losing work.
Mixed In Key writes Camelot codes into ID3 / iTunes comment fields. Those tags survive — SignalKey doesn't overwrite anything you've already tagged.
Drop your this-week's-promos folder onto BPM Finder + Key Finder. We process sequentially and return a CSV with BPM, key and Camelot per track.
Rekordbox: File → Import collection → choose CSV. Serato: drag the CSV onto a crate. Engine DJ: Library → Import metadata. Tags merge with the existing ones.
Pick 10 tracks both apps tagged. If 9+ of 10 keys match, you're done. If less, that's usually a relative-key difference (A minor vs C major) — both are correct, just different conventions.
Yes — we use the canonical 1A-12B notation Mixed In Key invented. A track tagged 8A in Mixed In Key will tag 8A in SignalKey, give or take the relative-key conventions where 8A and 5B can both apply.
Methodology: Researched April 2026 against the public Mixed In Key 11 product page and known industry behaviour. Pricing reflects the listed one-time licence at the time of writing. If anything in this comparison reads as inaccurate, please email hello@signalkey.io and we'll update.
Drop a song and see the analysis pass — BPM, key, Camelot, stems, MIDI, LUFS — in one go. Free forever.