What is Music Slow Downer?
Music Slow Downer is a free, web-based audio tool for musicians who want to practice challenging songs, solos, and techniques. Whether you’re decoding a blazing guitar solo, tightening a drum fill, or lining up vocal harmonies, you can slow things down without changing the pitch—and keep everything on your device.
Key Features
- Time-stretching: 0.25×–1.5× speed with pitch preserved
- Pitch shift: Transpose ±12 semitones (great for detuned recordings)
- A/B loop: Set loop points to repeat tough sections until they stick
- In-browser: No install—works entirely on your device
- Privacy-first: Audio never leaves your browser
Who Uses Music Slow Downer?
- Singers & Vocalists: Hear phrasing, vibrato, and harmonies without the rush
- Drummers: Catch ghost notes, fills, and subdivisions that blur at full tempo
- Pianists & Keyboardists: Master fast two-hand passages step by step
- Strings (Violin/Viola/Cello): Clarify bowing, shifts, and rapid runs
- Winds & Brass: Focus on tonguing, articulation, and breath control
- Guitarists: Decode solos, riffs, and complex techniques cleanly
- Bassists: Lock in grooves and refine timing with precision
- Music Students: Make transcription and ear training manageable
- Music Teachers: Demonstrate parts clearly and build confidence
- Cover Bands & Gigging Musicians: Learn setlists accurately, faster
- Producers & Arrangers: Dissect dense mixes and study arrangements
Technology
Built with modern Web Audio APIs and open-source libraries (e.g., WaveSurfer.js for waveform visualization and SoundTouch.js for high-quality time-stretching and pitch-shifting). All processing happens locally in your browser for maximum privacy and performance.
FAQ
Do I have to upload my audio?
No. Processing runs locally in your browser via Web Audio/WebAssembly. Your files never leave your device.
Which formats are supported?
Most common formats work in modern browsers (e.g., MP3, WAV, M4A, OGG). If a file won’t load, convert to WAV or MP3.
Which browsers are supported?
Latest versions of Chrome, Edge, Firefox, and Safari. Mobile support varies—desktop is recommended for best performance.
Our Mission
We believe every musician should have access to quality practice tools. That’s why Music Slow Downer is completely free. Optional ads help keep the lights on—while respecting your privacy.
Get in Touch
Have feedback or suggestions? We’d love to hear from you. Visit our support page or buy us a coffee to show your support.