KEY & BPM FINDER
Detect the key & BPM of any song instantly
Upload your audio and detect musical key and tempo in seconds. Pure browser processing — your files never leave your device.
What Is the Key & BPM Finder?
A free, browser-based audio analysis tool for DJs, producers and songwriters.
Know Your Library
Detect the musical key (scale) and beats-per-minute of any audio track — match songs, create mashups, and understand your music library faster.
100% Private & Secure
All analysis runs locally in your web browser, so your audio files are never uploaded to any server. Complete privacy for demos, stems and full tracks.
Fast & Accurate Results
Powered by an industry-proven audio analysis engine — reliable key and tempo estimates in seconds, using chroma analysis and multi-feature beat tracking.
What the Finder Detects
Musical Key Detection
Detects the tonal center and scale (major or minor) of your audio, making it easy to find harmonically compatible tracks for remixing, DJ sets or music theory study.
BPM & Tempo Analysis
Estimates the overall tempo in beats per minute using multi-feature rhythm extraction — a precise BPM value you can trust for grid alignment and beat matching.
Works in Your Browser
No installation, no signup, and no cloud required. Drag and drop an audio file and get results instantly on desktop or mobile.
Analyze a track in 3 steps
Drop your audio
Any format your browser can decode — MP3, WAV, FLAC, OGG, AAC or M4A, mono or stereo.
Analysis runs locally
The engine scans the first minute using chroma harmonic profiles and multi-feature beat tracking — fast and accurate for most songs.
Read the results
Key, scale and BPM appear in seconds — ready for Camelot mixing, mashups or pitch-matching acapellas to instrumentals.
Key Features of the Key & BPM Finder
Universal input
- —MP3, WAV, FLAC, OGG and other standard browser-playable formats.
- —First-minute analysis for fast results while maintaining accuracy.
- —Mono and stereo files handled automatically.
Professional-grade analysis
- —The same algorithms trusted by researchers and music-tech companies worldwide.
- —High-performance engine runs directly in the browser for fast, reliable results.
- —Open-source foundation with continuous community improvements.
Built for real workflows
- —DJs — prep set lists and harmonic mixing.
- —Producers — match acapellas to instrumentals.
- —Educators — teach music theory, rhythm and audio analysis.
Why Use This Key & BPM Finder
Totally Free
No paywalls, no watermarks, and no usage limits. Analyze as many tracks as you want.
No Server Uploads
Your creative work stays on your device. We do not store, log, or transmit your audio files anywhere.
Simple & Beautiful
A clean, dark-themed interface designed for focus. Upload, analyze, and read your results at a glance.
Accurate Enough for Pros
Professional-grade key and tempo detection trusted by creators for cataloging and pre-production.
Instant Feedback
Results appear within seconds of uploading. No queues, no slow cloud processing.
Cross Platform
Works on Windows, macOS, Linux, Android and iOS — anywhere with a modern browser.
Frequently asked questions
What is a Key & BPM Finder?
A Key & BPM Finder is an audio analysis tool that detects two fundamental musical properties of a track: its key (the tonal center and scale) and its BPM (the tempo in beats per minute). DJs and producers use this information for harmonic mixing, mashups, and remixing.
Is this Key & BPM Finder really free?
Yes. The tool is completely free to use with no hidden costs, subscriptions, or usage limits.
Do I need to install anything?
No. The entire tool runs inside your web browser. Just open the page, upload an audio file, and analyze it instantly.
Are my audio files uploaded to a server?
No. All processing happens locally on your device. Your files never leave your browser.
What audio formats are supported?
Any format supported by your browser's audio decoder, including MP3, WAV, FLAC, OGG, AAC, and M4A.
How accurate is the key detection?
We use a professional key detection algorithm that analyzes chroma harmonic profiles to estimate key and scale. It is highly accurate for most modern music, though complex or atonal tracks may produce ambiguous results.
How accurate is the BPM detection?
BPM is estimated using a professional rhythm analysis engine that combines multiple onset detection functions and beat-tracking algorithms. It works well for most genres with clear rhythmic structure.
Why does the tool only analyze the first minute?
Analyzing the first minute provides a fast, accurate estimate for the vast majority of songs while keeping the interface responsive. Most tracks maintain a consistent key and tempo throughout.
Can I use this for DJ harmonic mixing?
Absolutely. The detected key and scale can be used with Camelot notation or traditional circle-of-fifths mixing techniques to find harmonically compatible tracks.
Can producers use this to match vocals and instrumentals?
Yes. Knowing the key and BPM of an acapella and an instrumental makes it much easier to pitch-shift and time-stretch them to fit together.
Found the key & BPM? Put them to work
Your analysis is the starting point — take the track into the AceStep workspace and keep going.
Extend the Track
Make the song longer with AI-composed music that continues in the exact key and BPM you just detected — seamless intros and outros in ~20 seconds.
Open Extend Song → Remix-readySplit It into Stems
Now that you know the key, pull the track apart — clean vocal, drum, bass and instrument stems for harmonic mixing, mashups and sampling.
Open Get Stems →Try the Free Key & BPM Finder Now
Upload your first track and discover its musical key and tempo in seconds.
Analyze a Track →Free · Private · No usage limits