Song Key & BPM Finder

Key and BPM, at a Glance

Riffloop finds a song's key and BPM from the recording itself, on your own device, for a YouTube video, an audio file or a song on your phone. The key is read from the song's detected chords; the tempo comes from beat tracking of the actual performance, so it isn't rounded to a catalogue number.

• 🔑 The home key, major or minor, spelled the way a musician would (E♭, not D♯)
• 🥁 The real BPM of the version you're playing — 77 reads 77, not 80
• ▶️ Works on the YouTube video itself — no download, no upload
• 🎸 Comes with the chords, as guitar shapes, and six stems you can mute or solo
• 🎚️ Change the key in semitones or slow the tempo down in the same player
• 🆓 Free to start: the key and BPM in full on every song you split

How to Find the Key and BPM of a Song

Load the song, separate it, and read the key and tempo off the result. It takes the same few steps whether the song is on YouTube, in a file or on your phone.

1. Pick where the song is. A YouTube video: install the free Chrome extension. An MP3, WAV, M4A, FLAC, OGG or AAC file: open the Studio. A song on your phone: the iPhone or Android app.
2. Choose what to split. On YouTube, pick the section you want in the panel under the video; in the Studio and the apps, add the file or record the song playing.
3. Separate it. Riffloop splits the song into vocals, drums, bass, guitar, piano and the rest on your device, and reads the chords, key and tempo as it goes.
4. Read the key and BPM. They sit at the top of the result, next to the chords.
5. Sanity-check them. Tap your foot to the pulse and hum the note the chorus lands on. If either disagrees with your ear, the two sections below explain why.

A real capture from the Riffloop Android app: the detected key and tempo sit above the chord that's playing.

Key and BPM of a YouTube Video

To get the key and BPM of a YouTube song, open the video with the Riffloop extension, pick a section and separate it — the key and tempo show in the panel under the player. You don't download the audio or upload anything.

That is the step most finders skip. A typical key and BPM finder wants a file, so for a song you only have on YouTube it asks you to rip the audio somewhere else first and then upload it — two extra tools and a copyright question. Riffloop reads the audio that's already playing in your browser, on your own computer, and leaves the video where it is. The same panel then shows the chords on the video and the stem mixer, so finding the key is the first minute of practice, not a separate errand.

What stays private: the separation and the key and tempo reading run on your own computer or phone, and the song's audio is not sent to Riffloop. The privacy policy covers what an account stores.

Key and BPM on iPhone and Android

In the Riffloop app, pick a song and tap Find the chords. The top line shows the key and tempo read from the audio, for example D minor · 130 BPM, with the chords playing along underneath. You don't have to split the song first.

Split the song and the player adds the rest: the key button next to Speed moves the song up or down by as much as 12 semitones without changing the tempo, the speed control shows the new tempo in BPM, and the metronome clicks on the song's own beat instead of a fixed BPM. The audio is read on the phone, not uploaded.

Free to download for iPhone (iOS 26 or later) and Android 12 or later, with the same account as the Studio and the extension. The free plan splits sections of up to 60 seconds, five times a day; Pro splits whole songs.

Reading the BPM Honestly

BPM is the number of beats per minute. On music with a steady beat any good finder gets close; the disagreements are almost always about which level of the beat you count, not the speed of the song.

Half time and double time

A trap track might read 140 while you nod your head at 70; a hip-hop groove you feel at 90 has hi-hats that imply 180. Both numbers describe the same song. Count where your foot wants to tap and halve or double the reading to match — then set your practice tempo from that.

Rounded or real

Song databases list one tempo per catalogue entry, often a whole number someone typed in. Riffloop tracks the beats of the recording you're playing, so a song that sits at 77 reads 77. It matters most when you play along to a click: 77 against 80 drifts a full beat in about seven seconds.

Live takes drift

A band without a click often pushes into the chorus. The BPM of a loose live recording is an average; use it as your starting tempo and expect the click to feel a hair ahead or behind in places.

Reading the Key Honestly

A song's key is its home note plus major or minor — the chord the music keeps resolving to. Key detection is harder than tempo, and its misses are predictable: almost always a close relative of the real key, not a random one.

How Riffloop reads it: it detects the chords moment by moment, then picks the key those chords point to — rather than averaging the raw frequencies of the whole mix, which is easily thrown by a loud bass note or a busy synth.

Relative major and minor

C major and A minor share every note, so the notes alone can't tell them apart; only the resting chord does. Riffloop reads the key from the song's detected chords, which is steadier than guessing from raw sound, but on a song that hovers between the two, trust the chord it comes home to. Our guide to finding the key of a song by ear covers the resting-feel test in full.

A fifth away

The other common miss is the key a fifth up or down — G instead of C, say — because those keys share all but one note. If the label sounds almost right but one chord keeps clashing, check the neighbour.

Key changes and tuning

A finder gives one home key for the whole song. If the last chorus lifts a step, Riffloop's chord timeline follows the change while the key label stays on the original home key. And a recording that sits well off standard tuning — older tapes running fast, or a band tuned to A=432 — can push any detector to a neighbouring key; if your instrument sounds slightly sour against the record, check its tuning with a tuner.

How good is "good"?

Even research systems built only for key detection agree with human-labelled keys roughly three times in four on hard test sets, with most misses being the relative or fifth-away key (see the key-estimation results summarised here). Any finder that quotes near-perfect key accuracy is quoting an easy test. The honest workflow is: take the label, then confirm it by ear.

Key to Camelot Code

The Camelot wheel numbers the 24 keys 1 to 12, with A for minor and B for major. Same number means relative major and minor; one number up or down is a fifth away. Riffloop shows the key by name — this table converts it.

The table also explains the most common key-finder disagreement: when two tools give 8A and 8B, they agree on the notes and differ only on which chord is home.

What to Do With the Key and BPM

For a player, the key and BPM are where practice starts: they tell you which chords and scale to expect, how far to transpose, and what tempo to drill at. In Riffloop each of those is a control in the same player.

• 🎸 Play the chords. The key tells you the family of chords to expect; the chord finder shows the actual ones, in time, as guitar shapes.
• 🎤 Move it into your key. Knowing the song is in E lets you drop it two semitones to D for your voice — the key changer keeps the tempo where it is.
• 🐢 Set a practice tempo. A 120 BPM song at 75% speed is 90 BPM; slow it down with the pitch held and step back up.
• ⏱️ Count it in. A metronome at the detected tempo keeps you in time with the record.
• 🎚️ Hear your part alone. Solo the bass to confirm the home note, or mute your instrument and play the part over the band with the backing track maker.

A worked example

The finder reads E major, 128 BPM. You sing, and the chorus sits a little high, so you move the song down two semitones to D major — the tempo stays at 128. The bridge has a fast run you keep missing: loop those four bars at 75% speed, which is 96 BPM, until it's clean, then step back up through 85% and 100%. The key told you how far you moved; the BPM told you how fast you're really playing at each step.

Check It by Ear in Two Minutes

You can confirm a finder's answer without perfect pitch: tap for the tempo, hum for the key, and use the separated bass to settle any doubt.

1. Tap the pulse, not the drums. Tap where you'd nod your head for eight or so beats. If you land at half or double the reading, you're counting a different level of the same beat.
2. Loop the end of the chorus. Set an A-B loop over the bar where the chorus resolves.
3. Solo the bass. The note the bass settles on at that moment is almost always the home note.
4. Major or minor? Bright and settled says major; darker says minor. If the label said C major and the bass rests on A with a dark feel, it's A minor.
5. Play along for a verse. Strum the key's main chords along with the record. If one chord keeps clashing, try the key a fifth away.

For the full method — with no tool at all — see how to find the key of a song and how to learn songs by ear.

Riffloop vs Other Key and BPM Finders

Most key and BPM finders are built for DJs: upload a file, get a key, a Camelot code and a tempo for mixing. Riffloop is built for players: it reads the song where it already is and keeps going into chords, stems and practice.

If all you need is the tempo of a well-known track for a DJ set, a song database is quicker. If you want to play the song, the key and BPM are only the first line of what you need — which is the job Riffloop does.

Key and BPM Finder — FAQ

What people ask about finding a song's key and tempo: YouTube and Spotify, accuracy, half time, relative minor, Camelot codes and what's free.

If You Remember Four Things

• 1 A BPM that's double or half what you feel is the same song counted differently.
• 2 A key that's "almost right" is usually the relative major or minor, or a fifth away.
• 3 The chord the chorus comes home to beats any label.
• 4 The key and BPM are the start of practice: chords, transpose and tempo come next.

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