Local-first tools
Core audio analysis and editing tools read and decode files in your browser without sending the source song to our application server.
Free browser-based audio tools
Find a song's key and BPM, then change it
Detect musical key and tempo, change pitch or BPM independently, tap a beat, practice with a metronome, and edit audio. Each focused tool explains whether processing happens locally or uses cloud AI.
- Private by default
- Runs in your browser
- Free to use
KL
AnalyzedMidnight Motion.mp3
03:42 · Stereo
BPM
128
KEY
A min
CAMELOT
8A
01:1603:42
Choose a tool
Everything you need to work with key, tempo and audio
Start with the task you need. Each tool has a focused workspace, clear instructions and answers for common audio questions.
Private by design
Built with privacy in mind
Many of our audio tools decode and process files locally in your browser. When a feature needs cloud or AI processing, its tool page explains what is sent, stored, and retained.
Private by design
Built with privacy in mind
01
No file storage
Your source audio and generated results remain in browser memory and are not saved to an account or cloud bucket.
Direct local export
When a tool creates new audio, the browser prepares the download directly on your device.
One private workflow from analysis to export
Find the track's starting values, make the change you need and download the result without creating an account.
01
Choose your task
Open the dedicated finder, changer, cutter, joiner, tapper or metronome.
02
Process it locally
Audio analysis and transformation run in browser workers so the interface stays responsive.
03
Use the result
Read the detected values, practice at the measured tempo or download transformed audio.
Simple, transparent pricing
Subscribe monthly for the best value, try a credit pack first, or add Volume+ when you need more.
Credits refresh monthly. Manage or cancel your subscription anytime.
Free
$0forever
- Files saved for 6 hours
- Key & BPM Finder and Changer
- Audio Cutter and Joiner
- BPM Tapper and Metronome
- Voice Recorder
- Local processing on supported tools
Plus
$9.90/ mo
Credits1,000 / month
Unit price$9.90 / 1k credits
- Files saved for 7 days
- 1,000 credits every month
- Vocal Remover and Stem Splitter
- Audio Enhancer and Audio to MIDI
- Private creation history
- Commercial use rights for generated outputs
- Email support
Secure checkout powered by Stripe
ProPopular
$19.90/ mo
Credits2,500 / month
Unit price$7.96 / 1k credits
- Files saved for 30 days
- 2,500 credits every month
- Vocal Remover and Stem Splitter
- Audio Enhancer and Audio to MIDI
- Priority AI processing queue
- Private creation history
- Commercial use rights for generated outputs
- Priority email support
Secure checkout powered by Stripe
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We receive only the payment result and billing details needed to activate and manage your purchase.
30-Day Money-Back Guarantee
Full refund before using paid credits; otherwise, a proportional refund for unused paid credits. Refund terms
Key & BPM Lab FAQ
Common questions about our free browser audio tools.
Start with your song's key and BPM
Choose a local audio file and get the tempo, musical key, scale and Camelot code without uploading it.
Free to use. No account or audio upload required.