What You Can Analyze
BPM Detection
Instantly detect the tempo (beats per minute) of any song with high accuracy.
Key Detection
Find the musical key and scale (major or minor) for harmonic mixing.
Camelot Code
Get the Camelot code for easy DJ harmonic mixing reference.
Audio to MIDI
Extract notes from audio and convert to MIDI format for your DAW.
Pitch Shifting
Change the pitch of your song without affecting the tempo.
Tempo Change
Speed up or slow down your song without changing the pitch.
Supported File Formats
Audio Files
Video Files
Maximum file size: 200MB. All files are processed locally in your browser.
Why Use Toneify Song Analyzer?
100% Private
Your files never leave your device. All analysis runs locally in your browser.
Instant Results
Get BPM, key, and analysis in seconds. No waiting for server processing.
Completely Free
No signup, no limits, no hidden fees. Use as much as you want.
Who Uses a Song Analyzer?
DJs & Music Mixers
DJs use song analyzers to build organized libraries with BPM and key information for every track. Knowing the key enables harmonic mixing using the Camelot Wheel system — mixing songs in compatible keys creates smooth, musical transitions that keep dance floors energized. Knowing the BPM allows for seamless beatmatching without jarring tempo changes.
Music Producers & Beatmakers
Producers analyze songs to sample loops at the correct BPM, pitch-shift samples to match the key of their project, or understand how a reference track was constructed. Converting audio to MIDI lets producers recreate melodies and chord progressions from their favorite records directly in their DAW (Digital Audio Workstation).
Musicians & Music Students
Musicians learning songs by ear use key detection to identify what key to play in. Teachers use BPM analysis to set the correct metronome tempo for students. Guitarists and pianists use pitch shifting to transpose songs to a more playable key. Music students use these tools to analyze the structure and theory behind songs they love.
How Does Audio Analysis Work?
Understanding the technology behind song analysis helps you use it more effectively.
BPM Detection via Onset Detection
BPM detection works by analyzing the audio waveform to find "onsets" — the moments when notes or drum hits begin. By measuring the intervals between onsets and finding the most common pattern, the algorithm can determine the underlying tempo of the song. Modern BPM detection handles complex rhythms, syncopation, and tempo variations with high accuracy.
Key Detection via Chroma Analysis
Key detection uses a technique called chroma analysis, which measures the energy present at each of the 12 musical pitch classes (C, C#, D, D#, E, F, F#, G, G#, A, A#, B) across the song. This creates a "chroma vector" that is then compared against known key profiles using the Krumhansl-Schmuckler algorithm. The closest matching key profile indicates the song's key.
Audio to MIDI via Pitch Tracking
Converting audio to MIDI involves detecting the fundamental frequency of each note as it changes over time (pitch tracking), then quantizing those frequencies to the nearest MIDI note value. The result is a MIDI file containing the melody or notes extracted from the audio, which can be imported into any DAW or notation software.
100% Browser-Based Processing
All of Toneify's analysis runs entirely in your browser using JavaScript audio libraries. Your audio files are never uploaded to any server — they stay on your device throughout the entire analysis process. This means complete privacy, no file size upload limits, and instant results without waiting for server processing.
Song Analyzer FAQ
How accurate is the BPM detection?
Our BPM detection is highly accurate for songs with a clear rhythmic pulse, typically within ±1 BPM. Results may vary for songs with complex rhythms, live recordings with tempo fluctuations, or ambient music without a defined beat. For most pop, electronic, hip hop, and rock tracks, accuracy is excellent.
How accurate is the key detection?
Key detection accuracy depends on the musical content. Songs with clear harmonic content and simple key structures are detected with high accuracy. Songs that modulate between keys, use heavy chromaticism, or have complex harmonics may return the relative major/minor or a parallel key. Cross-referencing with the Camelot Wheel can help verify the result.
Is my audio file uploaded to your servers?
No. All audio processing happens entirely in your browser. Your file is read locally by the JavaScript code — it never travels over the internet to any server. Once you close the browser tab, the file data is completely gone. This makes Toneify safe for analyzing unreleased or copyrighted music.
What is the maximum file size?
The maximum file size is 200MB, which is sufficient for even high-quality FLAC files of full-length songs. Since processing is done in your browser, very large files may take longer to analyze depending on your device's CPU speed.
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