Free Online Chord Finder
Drop any audio file below and see the full chord progression - every chord, timed to the second. No account, no uploads - your file never leaves your device.
Detect Chords Now →What Is a Chord Finder?
A chord finder analyzes an audio file and identifies which chords are being played - and when. Instead of trying to figure out chords by ear (which takes years of ear training), a chord finder does the analysis automatically using audio signal processing.
Musicians use chord finders to learn songs by ear, producers use them to sample-flip reference tracks, and DJs use them to understand the harmonic structure of a track before mixing.
Common Chord Types
These are the chord types BeatKey Chord Finder can detect. Each has a distinct harmonic quality that shapes the feel of the music.
| Chord Type | Symbol | Sound |
|---|---|---|
| Major (C) | C | Bright, happy |
| Minor (Am) | Am | Dark, emotional |
| Dominant 7th (G7) | G7 | Tense, bluesy |
| Major 7th (Cmaj7) | Cmaj7 | Dreamy, smooth |
| Minor 7th (Am7) | Am7 | Mellow, jazz |
| Suspended 4th (Csus4) | Csus4 | Open, unresolved |
| Augmented (Caug) | Caug | Eerie, unstable |
| Diminished (Bdim) | Bdim | Tense, passing |
Why Use a Chord Finder?
Learn Songs Faster
Instead of spending hours figuring out chords by ear, upload the track and get the full chord chart in seconds. Great for guitarists, pianists, and keyboard players learning covers.
Sample Flipping
Producers chopping samples need to know the key and chords to layer new elements without clashing. Chord Finder identifies both so you can work in harmony.
Harmonic Mixing
DJs use chord and key detection to mix tracks harmonically - transitions that sound musical rather than dissonant. Pair with BeatKey BPM Detector for a complete mixing prep workflow.
Recognizing Common Chord Progressions
Once you know the chords in a song, you can identify its underlying progression. These six progressions appear in thousands of popular songs:
| Progression | In C Major | Genre |
|---|---|---|
| I-V-vi-IV | C-G-Am-F | Pop / Rock |
| I-IV-V | C-F-G | Blues / Rock |
| ii-V-I | Dm-G-C | Jazz |
| vi-IV-I-V | Am-F-C-G | Pop |
| I-vi-IV-V | C-Am-F-G | 50s / Doo-wop |
| i-VII-VI-VII | Am-G-F-G | Rock / EDM |
After running Chord Finder on a track, look for repeating chord groups to spot the progression. Most pop songs cycle through just 4 chords repeatedly.
How BeatKey Detects Chords
BeatKey Chord Finder uses Essentia - an open-source audio analysis library from the Music Technology Group at Universitat Pompeu Fabra, the same library used in professional music information retrieval (MIR) research.
The detection process:
- Your browser decodes the audio using the Web Audio API
- Essentia computes a Harmonic Pitch Class Profile (HPCP) - a chromagram showing pitch energy distribution over time
- HPCP frames are compared against chord templates (major, minor, 7th, etc.) using cosine similarity
- The best-matching chord template is assigned to each time segment
- Key is derived from the overall HPCP using the Key Extractor algorithm
Everything runs in WebAssembly - no server, no upload, instant results.
BeatKey Chord Finder vs Alternatives
| Feature | BeatKey | Paid tools |
|---|---|---|
| Free | ✓ | ✗ ($10-50/mo) |
| No file upload / privacy | ✓ | ✗ |
| Detects chords + key | ✓ | ✓ |
| Chord timeline | ✓ | ✓ |
| Export to text/JSON | ✓ | Varies |
| No install | ✓ | Varies |
| Works instantly | ✓ | ✓ |
Frequently Asked Questions
How accurate is the chord detection?
BeatKey Chord Finder is highly accurate for tonal music with clear harmonic content - pop, rock, R&B, jazz, EDM, and acoustic songs. Heavily distorted guitar, noise music, or percussion-only tracks may produce less reliable results. Accuracy improves with cleaner recordings.
What audio formats are supported?
BeatKey supports MP3, WAV, FLAC, OGG, AAC, and most browser-decodable audio formats. The file is decoded locally in your browser - no upload required.
Can I export the chord chart?
Yes. After analysis, you can export the full chord timeline as a text file or JSON. The text export is useful for printing; JSON is useful for loading into other tools or scripts.
Does it work for long songs?
BeatKey analyzes the full track for chord detection (chord content varies throughout a song, unlike BPM which is consistent). For very long files (>10 min), processing may take 20-30 seconds.