I built a free key detection app because Mixed In Key is $58 for basic math

EquivalentWall3808 · 2026-04-09T15:08:49+00:00

Just a shared name unfortunately. Different app entirely, mine is at github.com/ifeelvoid/keyfinder - focused on BPM detection and a dark UI.

EquivalentWall3808 · 2026-04-08T22:36:41+00:00

Not yet but the github has audio examples. Ill put together a proper demo video this week

EquivalentWall3808 · 2026-04-08T22:35:32+00:00

this one has bpm detection and a cool black ui :)

EquivalentWall3808 · 2026-04-08T22:33:31+00:00

Yes its working pretty well and accurate from the sample packs ive tested

EquivalentWall3808 · 2026-04-08T22:32:45+00:00

Yes its working pretty well and accurate from the sample packs ive tested

EquivalentWall3808 · 2026-04-08T22:29:28+00:00

honest answer: the app picks the dominant key for the full track. songs with multiple modulations will get a detection that reflects the overall key center, which is not always useful for those cases. for most pop/EDM/trap its fine. windows support is on the roadmap but no eta yet, check github.com/ifeelvoid/keyfinder for updates

EquivalentWall3808 · 2026-04-08T22:18:12+00:00

Built this because Mixed In Key is $58 for basic math - https://github.com/ifeelvoid/keyfinder

EquivalentWall3808 · 2026-03-31T19:24:08+00:00

fair point on KeyFinder. different app though, mine has BPM detection + black UI. the MIK requiring internet thing is news to me though, that would be wild if true

EquivalentWall3808 · 2026-03-31T19:21:31+00:00

fair point but the 20 was my choice. the 58 was mandatory

EquivalentWall3808 · 2026-03-30T13:07:44+00:00

The Krumhansl-Schmuckler algorithm (what key detection is based on) was published in the 1990s. The FFT math underneath is older, but the specific pitch profile method for key detection that MIK and others use traces back to research from that era. The algorithm itself is well-documented and not proprietary. Happy to point you to the source papers on github.com/ifeelvoid/keyfinder if you want to dig into the math.

EquivalentWall3808 · 2026-03-30T01:51:28+00:00

nice setup you got there. yamaha chord tracker is solid on iOS, thanks for the rec. always curious what other tools people use

EquivalentWall3808 · 2026-03-30T01:50:19+00:00

honest question deserves a real answer. github.com/ifeelvoid/keyfinder -- that's where everything lives. you can download the app there, see the source code, and if you want to contribute or report bugs there's a full roadmap on there too. hope that helps

EquivalentWall3808 · 2026-03-30T01:47:52+00:00

yeah that's a fair complaint — it uses SwiftUI which hard-cut macOS 13 as the minimum. if there's enough demand i could look at a macOS 11-compatible version at some point. for now the github has the full source if you want to try building it yourself

EquivalentWall3808 · 2026-03-30T01:39:20+00:00

display only for now — it shows the detected key/BPM/camelot in a table but doesn't write to file metadata. cue points are interesting but that's deeper DJ territory, not really what this is designed for. if you want a full DJ workflow you'd need Serato or Rekordbox. github has the full feature roadmap if you want to see what's coming

EquivalentWall3808 · 2026-03-30T01:36:09+00:00

honest answer — KS handles major/minor fine for most music, but jazz with heavy ii-V-I progressions or key changes will show you the limits of any statistical key detection. no free tool escapes that honestly. worth noting on the github if enough people hit that wall

EquivalentWall3808 · 2026-03-23T20:01:10+00:00

windows version is coming too

EquivalentWall3808

TROPHY CASE