About Mewzick

Mewzick is a small set of music tools built around one idea: do one thing, do it beautifully, and get out of the way. No cluttered dashboards, no accounts to make, no sign-up walls between you and the tool you opened the page for.

What’s here

  • Tuner — tune any instrument, string by string or against the full chromatic scale.
  • Tap Tempo — tap or press spacebar to find a BPM.
  • BPM Finder — detect tempo from your microphone or an audio file.
  • Key Finder — detect a song’s key the same way.
  • Chord Progressions — build, browse and hear chord progressions in any key.
  • Chord Chart — look up any chord’s guitar fretboard voicing, notes and intervals.
  • Circle of Fifths — see every key’s signature, scale and chords, and hear them.

Everything runs entirely in your browser — audio from your microphone or an uploaded file is analyzed on your device and never sent anywhere. See the Privacy Policy for the details.

How the tools work

We write our own audio analysis rather than wrapping a third-party service, and we say how it works so you can judge it:

  • Tuner: pitch is found with the McLeod Pitch Method, a normalized autocorrelation that copes with the strong overtones of plucked strings, and a tracker smooths the readings and ignores octave jumps. Details in how an online tuner works.
  • BPM Finder: the audio is split into short frames, the rise in spectral energy between frames marks the beats, and autocorrelation of that signal finds the tempo at which they repeat. When a half-time or double-time reading is about as likely, it is shown as an alternative.
  • Key Finder: the energy in each of the twelve pitch classes is added up and compared with the Krumhansl–Kessler key profiles for all 24 major and minor keys. The best match wins and a confidence score is shown. See how to find the key of a song for where it goes wrong.
  • Chord tools and the circle of fifths: built on standard music theory, with the voicings and key data computed in the page, not looked up from a server.

We test the analysis tools against a set of real songs with known keys and tempos, and we change an algorithm only when that test shows it helps.

The guides

The guides explain the music behind the tools: tuning, tempo, keys and chords. We write them to be useful to a player sitting with an instrument, and we correct them when we find a mistake or when a reader points one out.

On accuracy

BPM and key are estimates and aren’t always exact. If you need to be sure, double-check by ear or with another source.

Who’s behind it

Hi, I’m Nathan Thomson. I live in Utah and have played guitar, and dabbled in all sorts of other music production tools and synthesizers, for about 20 years. While working in a DAW I kept jumping between separate sites for tap tempo, key detection, chord charts and the circle of fifths. It sure would be nice, I thought, to have all of these in one place. That’s where Mewzick came from.

I use these tools myself while making music, and I hope they’re helpful to you too. Mewzick is published by Rubichron Games LLC, an independent studio, with no investors and no growth team.

Get in touch

Questions, feedback, or something broken? Reach us at privacy@mewzick.tools.