Summary

BPMKeyFinder is an online tool that analyzes audio files to determine their tempo (BPM) and musical key. It runs entirely in the browser, ensuring privacy by processing all data locally without uploading files.

How BPMKeyFinder Works

• Users drag and drop or select an audio file (MP3, WAV, FLAC, AIFF, AAC, OGG).
• Analysis is done locally via Essentia.js (from the Music Technology Group) compiled to WebAssembly.
• Results show BPM, musical key with Camelot notation, mode (major/minor), track duration, and confidence score.
• Optionally export analysis results as CSV for workflow integration.

Features

• Accurate BPM normalization within a practical range (60–180 BPM) with raw tempo values for expert users.
• Standard musical notation and Camelot codes for harmonic mixing decisions.
• Batch processing through queueing multiple files for analysis in browser.
• Confidence scores to assess detection reliability of tempo and key.
• CSV export and history available for Pro users.
• Mobile-optimized responsive web interface.
• Local processing for full privacy; no uploads or cloud processing.

Target Audience

Touring and club DJs needing verified tempo/key data for smooth transitions, music producers and editors aligning samples and stems, educators and choreographers planning classes or routines with reliable BPM/key info.

Pricing Model

Free tier allows up to 3 analyses per day with single file uploads and core features.
Pro subscription ($8/month) offers unlimited analyses, batch uploads, CSV export, analysis history, and priority support.