Find the chords
in any song
Drop a track. EarChord reads the chord progression, the key and the tempo. The audio is analysed on this device and never leaves your browser.
Chordify gives you 2 songs a day, or 4 with a free account, and file uploads are a Premium feature.EarChord has no daily limit and no account.chordify alternative
What EarChord reads from a file
- The chord progression
- A timeline of every chord the analyser found, with the time each one starts. Click any block to jump the playback there and check it against your ear. Copy the list as text or download it as a .txt file.
- The key
- One key for the whole track, worked out from how much each of the twelve notes is used across it and matched against the twenty-four Krumhansl-Schmuckler key profiles. The confidence figure is how far ahead of the runner-up it finished.
- The tempo
- Beats per minute, read from where energy rises across the track rather than from anything that listens for drums specifically. On material with no steady pulse it reports unclear instead of a number.
- Roman numerals
- On the chord progression finder, the same progression written relative to the key: I-V-vi-IV rather than C-G-Am-F. That is the form that transfers between songs, which is why it is worth reading twice.
How the detection works
The audio is cut into overlapping windows of about 190 milliseconds. Each window is transformed into a spectrum, and every frequency component between 55 Hz and 2 kHz is folded onto the twelve pitch classes. The result is a chromagram: how much C, C sharp, D and so on is sounding at each moment of the track.
Each frame of that chromagram is then compared against twenty-four templates, one major and one minor triad per root, and the closest match wins the frame. A short mode filter removes single-frame flickers, neighbouring frames carrying the same label are merged, and anything shorter than about a third of a second is dropped as noise. What is left is the timeline you see.
All of that is signal processing, not machine learning, and it is small enough to run in a Web Worker on the device you are already holding. Thirty-two seconds of audio takes about a tenth of a second.
What it will not tell you
The vocabulary is deliberately twenty-four major and minor triads. Widening it to sevenths and suspensions is a two-line change and it measurably makes ordinary pop and rock worse, because the extra templates win frames they should not. A song full of sus4 chords comes back as the nearest triads.
Inversions are not reported: a C major triad with E in the bass is labelled C, which is what most players want written on the page anyway. Distorted guitar is the hardest case, because distortion puts energy at pitch classes nobody fretted and a power chord has no third in it at all, so nothing in the signal says major or minor.
None of this is hidden behind a confidence score you have to trust. The timeline shows every chord it found and where, so the places it is guessing are the places you can hear it guessing.
Questions
- Is it really free, and is there a catch?
- It is free with no daily limit and no account. The reason is structural rather than generous: the analysis runs on your own processor inside your own browser, so the thousandth song you run costs us exactly what the first one did, which is nothing. Tools that fetch and analyse audio on a server have to meter it, because for them every song is a bill.
- Does my audio get uploaded?
- No. There is no upload step in the product at all. Your browser decodes the file and the chord detection runs in a Web Worker on your machine. You can confirm it: open your browser devtools, watch the network tab, and drop a file in. Nothing goes out.
- Which file types work?
- Anything your browser can decode, which in practice means MP3, WAV, M4A, AIFF, FLAC and OGG. There is no fixed size limit; the file stays in the tab, so your device memory is the real ceiling.
- How accurate is it?
- On clear recordings with one or two harmonic instruments, most chords land. It degrades on dense, loud, heavily compressed mixes, and it reports only major and minor triads, so a seventh or a suspension comes back as the triad closest to it. The timeline shows what was detected rather than hiding it, so you can check the parts that matter.
- Can I paste a YouTube link?
- Not on the site. Fetching video audio on a server is what creates the bandwidth cost that forces other tools into daily limits. The Chrome extension solves it the other way round: it reads the audio the YouTube player is already producing in your own tab and shows the chords under the video.