Find the key of any song, instantly
Drop an MP3, WAV, FLAC, or M4A and get the musical key in seconds — free, private, and right in your browser. No upload, no signup.
Drop an audio file here or click to add
MP3, WAV, FLAC, M4A
Why knowing your song's key matters
Once you know a track's key, a lot of decisions get easier — which notes to add without clashing, which reference tracks will actually mix well together, and how to transpose a part so it fits. Guessing by ear works if you have trained relative pitch, but for AI-generated songs, quick reference checks, or just double-checking your own ear, an instant, consistent answer beats trial and error.
How key detection works
This tool analyzes the track's harmonic content — which pitches are present and how strongly — and builds a 12-note profile (a chromagram) of the whole song. It then compares that profile against the well-established Krumhansl-Schmuckler key profiles for all 24 major and minor keys, and picks the best match. This catches the overall tonal center even when a track doesn't hold a single obvious chord for long.
Key detection for Suno & Udio tracks
AI music generators don't reliably report the key anywhere in the file or app. If you want to layer a Suno song into a mix, write a harmony part, or match it with a reference track, this tool gives you the key instantly instead of picking it out by ear.
How to find the key of a song
One step: drop the file. Everything happens locally in your browser — your track is never uploaded to a server.
1. Drop your track
MP3, WAV, FLAC, or M4A. The file is decoded and analyzed with the Web Audio API — nothing leaves your device.
2. Get the key instantly
The tool builds a harmonic profile of the track and matches it against all 24 major and minor keys, showing the best match with a confidence score.
3. Use it anywhere
Write a harmony part, set your DAW's key signature, pick compatible reference tracks, or head over to mastering and a lyric video for the same track.
What people use a key finder for
Once you know the key, a lot becomes possible — from writing to mixing to just satisfying your curiosity about a track.
Production & songwriting
Know the key before you add a bassline, harmony, or lead melody so it doesn't clash with what's already there.
Remixing & sampling
Find the key of a Suno song or sample before you build a remix around it, so new layers stay in tune with the original.
Harmonic mixing for DJ sets
Know the key of each track before you sequence a set so transitions between songs sound intentional instead of clashing.
Frequently asked questions
Key detection, answered.