Find the Chords Behind Any Song

What Is the Audio Chords Detector?

The Audio Chords Detector is a free online chord finder that listens to a song and turns it into a bar-by-bar chord chart. It detects the chords of any MP3 or audio file, along with the key, tempo (BPM) and time signature. You can play the song with the chords highlighted, transpose them, see piano and guitar chord diagrams, and download the chart as a PDF. It is useful for guitarists, pianists, singers, music teachers and anyone who wants to learn a song by ear. It works in four simple steps: upload your song, choose the settings, let the tool analyse it, then play along or download the chart.

How to Detect Chords from a Song: Step by Step

Step 1: Upload your song. Click Upload track or drag and drop a file onto the page. The chord detector accepts MP3, WAV, FLAC, M4A, AAC, OGG, MP4 and MOV files.

Step 2: Choose the model. Keep Auto for most songs. Pick Vocal plus Instrumental Songs for tracks with a lead singer, or Instrumental Songs for piano, guitar or band recordings without vocals.

Step 3: Choose the chord complexity. Basic gives major and minor chords only. Standard adds sevenths, suspended, add9, diminished and slash chords. Extended adds sixths, ninths, augmented chords and more.

Step 4: Wait for the analysis. A progress bar shows the status. Long or complex songs can take a little time, so if your browser shows a “page unresponsive” message, click Wait.

Step 5: Read the results. The detected key, tempo (BPM) and time signature appear first, followed by the full bar-by-bar chord chart.

Key, BPM and Time Signature Detection

The tool detects the musical key, the tempo in beats per minute and the time signature, including 4/4, 3/4, 7/8 and other odd meters. Each result has a confidence ring: green means high, orange means medium and red means low. Every chord also has its own confidence value in the Chord Timeline View. Use these values as a guide and confirm doubtful chords by ear.

Read the Chord Chart and Timeline View

The Chart view shows each chord as a colour-coded block, and the block width matches how long the chord is held. A chord that continues across a bar line is repeated on the first beat of the next bar. The Chord Timeline View lists the same chords bar by bar, with beats, confidence values and faded names for held chords. Use the zoom buttons to resize the blocks and click any chord to jump to that point in the song.

Play Along, Transpose and Learn Chord Shapes

Press play to hear the song while the current chord is highlighted, and watch the orange pointer move across the chart. Switch on Follow to keep the playing chord in view, and drag the slider to move to any position. Open the Shapes strip to see piano and guitar diagrams for any chord, including slash chords such as C/E. When an easier version of a hard chord exists, use the Simpler option button to switch to it. The Transpose buttons shift all chords by up to 11 semitones, which suits singers and capo players, and clicking the transpose value resets it. Keyboard users can reach every control with Tab, move between chords with the arrow keys and press Enter or Space to play.

Download the Chord Chart as PDF or Text

Click Download to save the chord chart as a PDF with piano diagrams, guitar diagrams or both, or as a plain text file. The download uses your chosen chord complexity and transpose setting, and the PDF shows each chord’s length in beats and bars.

Technical Details and Limits

The detector runs entirely in your browser using digital signal processing, so your audio file is not uploaded to a server and no sign-up is needed. It reads the audio as chroma (pitch-class) features, tracks the beat to find bars and then chooses the most likely chord for each beat with a smoothing step, so single-beat errors are reduced. Only the first 10 minutes of a track are analysed, and the page shows a notice when a song is longer. Uploading another file replaces the previous results. For the best accuracy, use a clean, full-quality recording.