The fastest way is to let software listen: choose the song file in the free BPM and key finder and it shows the key (for example "A minor") and the tempo in a few seconds, without uploading the file. By ear, find the note that feels like "home" (where the song wants to end), match it on a piano app, and decide whether the song sounds major or minor. That home note plus major or minor is the key.

Key takeaways

  • A key has two parts: the home note (tonic) and the scale type, usually major or minor.
  • The last note or chord of a song is very often the home note. Start there.
  • Every major key shares its notes with one minor key (C major and A minor, for example), so tools and people sometimes confuse the two.
  • Songs that change key halfway, or that use scales outside the Western major/minor system, can give unclear results.
  • For singing, the key name matters less than the song's highest and lowest notes. Use the key to talk to musicians and karaoke machines; use your range to decide if the song fits.

Method 1 — Use a free key finder (10 seconds)

  1. Open the BPM and key finder on your phone or computer.
  2. Choose the song file (MP3, M4A or WAV, up to 8 minutes).
  3. Wait a few seconds. You'll see the key, how sure the result is (Clear, Likely, or Unclear), the related key that mixes well with it, and the tempo in BPM.

How it works: it listens to the middle 90 seconds of the song, past any intro, measures how much of each of the 12 notes the music uses, and compares that pattern with the typical patterns of major and minor keys. It all runs in your browser, so the file stays on your device.

If the result says Unclear, the song may change key, or it may be built on a scale the major/minor model doesn't fit well, such as an Arabic maqam or an Indian raga. In that case it shows the closest Western key.

Method 2 — Find it by ear (3 steps)

You need a piano or keyboard app on your phone. It takes practice the first few times, then gets quick.

1. Find the home note. Play the song and, at the end of the chorus or the end of the song, hum the note that sounds finished, as if the song could stop there. Keep humming it while the music plays: it should sound settled almost everywhere.

2. Match it on the keyboard. Tap keys until one matches your hummed note. Its letter is the home note. Don't worry about which octave; any C is a C.

3. Major or minor? Play the home note together with the note 4 keys above it (counting every black and white key). If that sounds bright and matches the song's mood, the key is major. If the note 3 keys above sounds more like the song, it's minor. Very roughly, major sounds bright and settled, minor sounds darker or more emotional, but plenty of happy songs are minor, so trust the match, not the mood.

Method 3 — Look at the chords

If you can find the song's chords online or from a musician, the key is usually:

  • The chord the song ends on, and
  • The chord that appears most, especially at the end of the chorus.

A song whose chords are mostly C, F, G and Am, ending on C, is almost certainly in C major. If the same chords end and settle on Am, it's A minor. Be careful with chord sites: many show songs in an easier key for guitar with a capo, not the key of the recording.

Why key finders sometimes disagree

  • Relative keys. C major and A minor use exactly the same notes, so a tool may pick the wrong one of the pair. The key finder shows the related key next to the result for this reason.
  • Key changes. Many pop songs move up a step for the last chorus. A tool that listens to a different part may name a different key.
  • Tuning. Some recordings are tuned slightly above or below standard pitch (A = 440 Hz), which can push a borderline result to the neighbouring key.
  • Non-Western scales. Maqam-based Arabic songs, ragas and many folk styles use notes or intervals the major/minor model doesn't describe, so any Western key name is only an approximation.

What singers do with the key

  1. Tell the karaoke machine or musician. "Can we do it a tone lower?" is much easier to act on when everyone knows the original key.
  2. Change the key to suit your voice. Lower or raise the song a semitone at a time with the free key changer; see how to change a song's key to fit your voice.
  3. Check the top note. Two songs in the same key can sit an octave apart in the melody. Compare the song's highest sung note with your comfortable top from the vocal range test.
  4. Medleys and mash-ups. Songs in the same key or in related keys blend well one after another.

Tempo, too

The same tool shows the tempo in beats per minute (BPM). Some songs read as half or double their real tempo, so it shows both; pick the one you can comfortably tap your foot to. If a fast song is hard to learn, slow it down without changing its key with the free tempo changer.

Current price and limits

Every new account can make and hear 2 whole songs free, once per account, each up to 4 minutes, with no card. Downloads need a paid plan. Starter is $8.99 a month for 30 finished minutes (about 7 songs) and Creator is $19.99 a month for 90 minutes, or $89.99 and $189.99 paid yearly. Both include WAV and song-card video downloads, one guided correction per song and free re-downloads. Minutes refresh monthly without rollover. Prices show in your currency where available; pricing and Stripe checkout confirm the total before you pay. See the refund policy.

Frequently asked questions

How accurate are online key finders? For songs with a clear harmony that stay in one key, they're usually right or off by the relative key (C major vs A minor). Results get less reliable for songs that change key, sparse acoustic recordings, and music built on non-Western scales.

Is the key the same as the first note of the song? Not necessarily. Many melodies start on another note. The home note is where the song feels resolved, most often at the end.

What does "C# minor" or "Bb major" mean? The letter (with ♯ sharp or ♭ flat) is the home note; "major" or "minor" is the scale. C# and Db are the same note with two names.

Does the key tell me if I can sing a song? Only partly. The melody's highest and lowest notes decide that. Find your range with the vocal range test, then compare.

Is my song uploaded? No. The BPM and key finder works in your browser and the file never leaves your device.

Hear any song sung in your voice. Your first 2 songs are free to make and hear.