Key & BPM Lab is a free, browser-based suite of audio tools for finding, changing, and editing the key, tempo, and audio of music files, with optional AI tools available through paid credits.
What is Key & BPM Lab?
Key & BPM Lab is a collection of web audio tools that runs in your browser and works with local audio files. The core functions are detecting a song's BPM, musical key, scale, and Camelot code, and changing tempo or key without affecting pitch. Outputs include on-screen analysis results and downloadable WAV files. The service is made by Key & BPM Lab and includes both free essential tools and paid AI-powered features.
Key Features
- Key & BPM Finder — Analyzes a local audio file to detect tempo (BPM), musical key, scale, and Camelot code; processing runs locally in the browser.
- Key & BPM Changer — Changes tempo without changing pitch, or transposes a track to a different key, and exports the result as a WAV file.
- Audio Cutter and Joiner — Trims and merges audio files directly in the browser, with local processing and export.
- Voice Recorder — Records audio through the browser and exports it, all without leaving the site.
- BPM Tapper and Online Metronome — Manual tempo measurement and accurate rhythm practice tools that need no audio file.
- AI-powered tools (paid) — Includes Vocal Remover & Stem Splitter, Audio Enhancer, and Audio to MIDI, which use cloud or AI processing and require credits from a subscription or one-time pack.









