Song Key Finder
Find the musical key of any song by entering or pasting its chord progression.
Supports major, minor, 7ths, diminished chord symbols.
Find the Musical Key of Any Chord Progression
The Song Key Finder helps you identify the musical key of a song by analyzing its chord progression. Simply paste a sequence of chords, such as C, Am, F, G, and the tool determines the best-fitting major or minor key, calculates a confidence score, displays the relative key, lists the scale notes, and highlights the corresponding root notes on a piano keyboard.
Whether you’re writing original music, learning cover songs, arranging chord progressions, or studying harmony, the Song Key Finder removes the guesswork from key analysis. All calculations are performed directly in your browser, allowing you to analyze chord progressions instantly without installing music theory software.
How the Song Key Finder Works
Using the tool is quick and straightforward.
- Enter or paste your chord progression into the text box.
- Separate chords with commas, spaces, or new lines.
- Click the analysis button or use one of the preset progressions.
- Review the detected song key and confidence score.
- Explore the relative key, scale notes, and piano visualization.
- Use Copy Analysis if you’d like to save your results or Reset to load the default progression.
Behind the scenes, the tool compares your chord progression against the diatonic chords of all 24 major and minor keys. It scores each possible key based on how many of your chords naturally belong to that scale, then returns the highest-scoring match.
If you’d like to understand how musical keys are built, What Is Pitch in Music? and Musical Intervals Explained provide useful background.
Understanding Your Results
Once the analysis is complete, the tool displays several helpful results.
| Result | Description |
|---|---|
| Song Key | The major or minor key that best matches your chord progression. |
| Confidence Score | Percentage showing how closely the entered chords fit the detected key. |
| Relative Key | Displays the corresponding relative major or minor key. |
| Scale Notes | Lists the seven notes that belong to the detected scale. |
| Piano Visualizer | Highlights the root notes on an interactive piano keyboard. |
For example, the progression C – Am – F – G produces C Major with a 100% confidence score because every chord belongs naturally to the C major scale. The relative key displayed is A Minor.
To explore how notes relate to scales, you may also find the Music Note Frequency Chart and Chromatic Scale Explained helpful.
Confidence Score Explained
The confidence score indicates how well your progression matches the detected key.
A higher percentage means more of the entered chords belong naturally to that key’s diatonic harmony. For example:
- 100% Match – Every entered chord fits the detected key.
- High Match – Most chords belong naturally to the scale.
- Lower Match – The progression may include borrowed chords, modal harmony, or key changes.
This score helps musicians quickly judge how strongly a progression supports the suggested key without manually comparing every chord.
If you’re learning to recognize notes and chords by ear, How to Identify Musical Notes and How to Tell What Note Is Playing are excellent companion guides.
Practical Uses for Songwriters and Musicians
The Song Key Finder can assist with many common music tasks, including:
- Identifying the key of a chord progression.
- Studying harmony in popular songs.
- Finding the relative major or minor key.
- Building melodies that match existing chords.
- Checking whether original progressions stay within one key.
- Learning basic music theory through real examples.
Because the analysis runs entirely in your browser, your chord progressions are processed locally without being uploaded to a server.
For a deeper understanding of harmony, you can also explore Perfect Fifth Interval, Major Third Interval, and Perfect Fourth Interval.
Frequently Asked Questions
How does the Song Key Finder determine the key?
The tool compares your chord progression against the diatonic chords of all major and minor keys and returns the highest-scoring match.
What does the confidence score mean?
It shows how many of your entered chords belong naturally to the detected key. Higher percentages indicate a stronger harmonic match.
Can I enter chords in different formats?
Yes. Chords can be separated by commas, spaces, or new lines.
What is a relative key?
A relative major and minor key share the same set of scale notes while having different tonic notes.
Does the tool upload my chord progression?
No. All chord parsing and music theory calculations run entirely within your browser.