BPM Finder is a browser-based tempo analyzer aimed at DJs, producers, fitness instructors, video editors, and anyone who needs an accurate beats-per-minute reading without installing software. Instead of uploading audio to a remote server, the tool decodes and downmixes files locally using the Web Audio API, then runs onset and rhythm feature extraction plus a neural tempo model entirely client-side. That design keeps private or unreleased material on your machine while still returning precise, decimal-level BPM values with confidence scores.
The workflow is built around three input modes. File analysis handles MP3, WAV, FLAC, AAC, OGG, and M4A clips up to roughly 50 MiB each, and can process up to 50 files in a sequential batch queue—useful for tagging an entire sample library or preparing a full setlist. Tap Tempo converts rhythmic taps into a stable reading, and Microphone mode listens to live audio such as a rehearsal, a record playing in the room, or a class playlist.
The project publishes its own benchmark methodology and sealed test results, comparing detection accuracy against well-known online music databases and desktop key/BPM software. It also notes the boundaries of those numbers honestly, and a companion Key Finder is available for harmonic mixing. Everything runs without registration and stays free to use in the browser.
