StudioWavePro — Online Audio Editor with 48+ Studio Tools

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StudioWavePro’s Key Detector analyzes which of the 24 musical keys (12 major, 12 minor) best matches your track. It works the way music-theory research says to do it: the audio is reduced to a chroma vector — how much energy each of the 12 pitch classes (C, C#, D…) carries across five octaves — and that fingerprint is correlated against the Krumhansl-Kessler key profiles, the standard model of how strongly each note implies a key.

You get more than a single answer: the detected key comes with a confidence percentage, the three closest alternative keys, and a bar chart of the pitch-class distribution so you can sanity-check the result yourself. That matters because some keys are genuinely ambiguous — a song in A minor uses the same notes as C major — and seeing the runner-up tells you when to double-check by ear.

When to use

Find the key of a song before learning it on guitar or piano.
Check whether two tracks are key-compatible for a DJ transition or mashup.
Pick the right key for a vocalist before transposing a backing track.
Tag your sample library or beat collection with correct key information.
Verify the key of your own composition or beat before writing a melody over it.

How to use

Click "Open Key Detector" below to launch the editor.
Drop in any audio file — MP3, WAV, OGG, M4A and FLAC are all supported.
Analysis starts automatically and takes a few seconds depending on track length.
Read the detected key, its confidence score, and the alternative candidates.
Check the pitch-class chart: the tallest bars should be notes that belong to the detected key.

Tips

Relative keys (A minor / C major) share every note, so they’re the most common confusion — if the detector’s top two candidates are relatives, listen for whether the song feels resolved on the minor or the major chord.
Tracks with heavy percussion and little harmonic content (drum loops, some hip-hop) give low confidence scores — there simply isn’t much pitch information to analyze.
Key changes mid-song (a final-chorus modulation, for instance) blur the result, since the analysis covers the whole file. Trim the file to one section first for a cleaner reading.
Pair this with the Tempo Detector to get both key and BPM — together they tell you everything needed for harmonic mixing.
Want the song in a different key once you know it? Pitch Shift moves it by exact semitones without changing the tempo.

Frequently asked questions

How do I find out what key a song is in?: Drop the song into the Key Detector and wait a few seconds. It returns the most likely key (for example "F# minor"), a confidence score, and the closest alternatives. No musical training or signup needed.
How accurate is the key detection?: For harmonically clear material — pop, rock, EDM, acoustic music — accuracy is high, and the confidence score tells you how decisive the result is. Sparse or very percussive tracks, detuned recordings, and songs that change key are harder, which is why the alternatives are shown.
What does the confidence percentage mean?: It measures how far ahead the winning key is of the runner-up. A high score means one key clearly dominated; a low score means two or more keys fit almost equally well — often a relative major/minor pair — and it’s worth checking the alternatives by ear.
What is the pitch class distribution chart?: It shows how much energy each of the 12 notes (C through B) carries in your track. In a song in C major you’d expect tall bars on C, E and G. It’s the raw evidence the detector based its decision on, so you can verify the result yourself.
Why does it say my A minor song is in C major?: A minor and C major contain exactly the same notes — they are "relative" keys. Algorithms (and humans) tell them apart by which note feels like home, which is subtle. If the detector picks the relative of what you expect, check which chord the song ends on.
Can I detect the key of just one section of a song?: Yes — use the Trim tool first to cut the file down to the section you care about (a chorus, for example), then run the Key Detector on the result. This also helps with songs that modulate between sections.
Does this also detect the BPM?: No — key and tempo are separate analyses. Use the Tempo Detector tool for BPM; together they give you the full harmonic-mixing picture for DJ sets and mashups.

StudioWavePro is a complete audio editor with 48+ studio-grade tools in one workspace. Trim, master, EQ, time-stretch, denoise, remove vocals, detect BPM and musical key, generate metronomes, and more. Editing tools

Audio Trimmer — crop a track to a selected region

Mute Section — silence a selected region

Reverse Audio — play the track backwards

Fade In/Out — ramp volume at start or end

Silence Trimmer — strip leading and trailing silence

Silence Gap Inserter — insert silence at a chosen position

Audio Looper — repeat a section N times

Audio Splitter — cut a track into multiple parts

Audio Merger — join multiple files end-to-end

Silence Splitter — auto-split at silent gaps

Crossfade Joiner — join clips with overlapping fades

Time and pitch

Speed Changer — speed up or slow down (with optional pitch preservation)

Pitch Shift — change pitch without changing tempo

Tempo Detector — estimate the BPM of a music track

Key Detector — estimate the musical key

Metronome Generator — create a click track at any BPM

Effects

Volume — make a track louder or quieter

Bass Boost — lift the low end

Treble Boost — lift the high end

Low Pass Filter — cut off high frequencies

High Pass Filter — cut off low frequencies (remove rumble)

Equalizer (3-band) — low / mid / high tonal shaping

Equalizer (10-band) — fine-grained tonal control

Echo — add repeating echoes / delay

Distortion — overdrive, fuzz, and lo-fi grit

Stereo Balance — shift the L/R center of a stereo mix

Stereo Widener — make stereo narrower or wider

Vocal Remover — karaoke (center-channel removal)

Hum Remover — strip 50/60 Hz mains hum

Mastering and analysis

Normalize — maximize volume without clipping

Compressor — even out loud and quiet parts

Loudness Meter — measure peak, RMS, and LUFS

Mono Converter — collapse stereo to mono

Channel Extractor — pull L, R, Mid, or Side

Sample Rate Converter — resample to 44.1, 48, or 96 kHz

Polarity Inverter — flip waveform for phase alignment

DC Offset Remover — center waveform around zero

Audio Visualizer — render an animated video from audio

StudioWavePro supports MP3, WAV, OGG, M4A, and FLAC files. Exports include WAV and MP3. This app requires JavaScript to run. Please enable JavaScript in your browser.