BPMKeyFinder is a web-based tool that allows users to verify the tempo, musical key, and harmonic compatibility of audio tracks directly in their browser. It is designed for DJs, producers, educators, and music professionals who need quick, accurate, and private analysis without uploading files to external servers.

• Analyzes audio files locally using Essentia.js for high accuracy
• Supports multiple formats (MP3, WAV, FLAC, AIFF, AAC, OGG)
• Provides BPM, key, Camelot code, mode, confidence ratings, and raw estimates
• Enables batch processing and CSV export for library management

The process involves dragging and dropping a track, which is then analyzed locally in the browser. Results include tempo, key, Camelot code, and confidence level, helping users plan harmonic mixes and set accurate tempos. The tool offers a free tier with limited analyses per day and a Pro plan for unlimited use, batch processing, and metadata management. Its target audience includes touring DJs, music producers, educators, and choreographers seeking privacy-first, reliable music analysis to streamline their workflow.

Benefits include privacy (no files leave the device), high accuracy validated by research and DJ sets, and ease of use across devices. It is ideal for preparing sets, remixing, or educational purposes.