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Online Chord Progression Detector.

Analyze a complete song into an editable, time-aligned major and minor chord sequence — then transpose the display, show capo shapes and export your corrections.

Before-and-after illustration of Online Chord Progression Detector: Harmonic recording becomes Editable progression through Estimate chord segments.
Before → process → afterSee the signal story, then hear it in the workspace.

MUSICAL GRID MAP

Chord Timeline Map

Connect detected or generated events to a musical grid. Pitch, rhythm and harmony become useful only when event timing, confidence and editable musical labels stay visible together.

Before-and-after illustration of Online Chord Progression Detector: Harmonic recording becomes Editable progression through Estimate chord segments.
Harmonic recordingEstimate chord segmentsEditable progression
A musical-event view: source cues become timed notes or beats, then resolve into an editable pattern rather than a hidden one-click guess.
Open the full signal breakdownBest source, processing logic, limits and three-pass listening check
  1. Harmonic recording

    Start with the right material

    Learning a progression, drafting a transcription, checking harmony before a remix and exporting a time-coded chord outline for later correction.

  2. Estimate chord segments

    Understand the transformation

    A gap-free scan aggregates overlapping Hann-window FFTs into at most 1,200 tuning-aware twelve-bin chroma frames, scores 24 major/minor templates plus N, then applies a Viterbi path and minimum-duration smoothing.

  3. Editable progression

    Verify the usable result

    A confidence-labelled chord timeline with manual edit/merge/split controls, transposed or capo-oriented display and TXT/CSV/JSON exports containing exact boundaries and analysis settings.

Segment confidence

Where this workflow stops

This is conventional-DSP estimation, not perfect chord recognition. One global tuning offset is estimated around A440, but tuning changes, extensions, inversions, bass movement, dense mixes, percussion and keys outside the 24-template major/minor vocabulary can still confuse it.

THREE-PASS CHECK

Make the final decision by ear

  • Confirm tempo, downbeat and key before trusting labels.
  • Review low-confidence events by ear and correct them manually.
  • Import the result into its target instrument or DAW before committing.

How to detect a chord progression

  1. Drop a song or recording and let the local full-file analysis finish.
  2. Click any timeline time to seek, then check each estimated major, minor or no-chord label by ear.
  3. Edit labels, split a change that needs a tighter boundary, or merge neighbouring segments.
  4. Choose a transpose interval and capo fret, then export TXT, CSV or JSON.

This online chord progression detector maps overlapping FFT windows into 12 pitch classes, bounds that evidence into at most 1,200 timeline frames, compares those frames with 24 major and minor triad templates, and smooths brief label changes. Unlike a song key finder, it follows harmony across time instead of returning one global key. Unlike melody transcription, it estimates simultaneous chord tones rather than a single note line. Processing covers the complete decoded file and stays in your browser.

Automatic chord recognition is an aid for practice, arrangement and first-pass transcription. Dense production, inversions, suspended or extended chords, quiet passages and recordings that change tuning can produce ambiguous labels; the tuning estimate is global. The visible confidence is an uncalibrated score margin, not a probability or accuracy promise. Edit the timeline and trust your ears before performing or publishing a chart.

Online Chord Progression Detector: quick answer and technical limits

Quick answer: A local full-file chord progression detector that estimates a changing timeline of major, minor or no-chord segments instead of returning one global song key.

Best for
Learning a progression, drafting a transcription, checking harmony before a remix and exporting a time-coded chord outline for later correction.
How it works
A gap-free scan aggregates overlapping Hann-window FFTs into at most 1,200 tuning-aware twelve-bin chroma frames, scores 24 major/minor templates plus N, then applies a Viterbi path and minimum-duration smoothing.
What you get
A confidence-labelled chord timeline with manual edit/merge/split controls, transposed or capo-oriented display and TXT/CSV/JSON exports containing exact boundaries and analysis settings.

Know before you use it: This is conventional-DSP estimation, not perfect chord recognition. One global tuning offset is estimated around A440, but tuning changes, extensions, inversions, bass movement, dense mixes, percussion and keys outside the 24-template major/minor vocabulary can still confuse it.

Privacy: Selected audio is processed in this browser and is not uploaded to AudioWrench. Normal page assets can still be requested as described in the privacy notice. Privacy details →

FAQ

How do I find the chord progression of a song?
Drop an audio file, wait for the full-file analysis, then review the time-aligned chord segments. Click a time to seek, change an estimated label, split or merge a segment, and export the corrected progression when it matches what you hear.
How accurate is automatic chord detection?
The labels are estimates, not ground truth. Clear major and minor harmony is easier to classify than dense mixes, inversions, extended chords, key changes or weakly tonal audio. Confidence is a relative score margin, not a calibrated probability, so confirm important changes by ear.
Can I transpose the chords or show capo shapes?
Yes. The transpose control shifts the displayed concert chords without changing the audio or the detected source labels. Set a capo fret to show the simpler chord shapes that produce those concert pitches, and the selected display settings are included in every export.
Is the chord progression detector free and private?
It is free with no signup. The selected audio is decoded and analyzed on your device and is not uploaded to AudioWrench. Normal page assets can still be requested as described in the privacy notice, and runtime depends on the file and device.