Change the tempo, keep the key. Stretch any song from 25% to 200% with the pitch locked - built for learning solos, transcribing, and drilling fast passages. Nothing uploads.
Drop an audio file here, or click to choose
MP3, WAV, AAC/M4A, OGG - stays on your device
Slow the passage until every note is clean - not almost clean - then raise the tempo in steps of five to ten percent, dropping back a step whenever mistakes reappear. Speed you cannot play accurately is not speed, it is rehearsed error. Find the song's real tempo with the BPM counter, keep time against the metronome, and if you are working out the notes by ear, the pitch shifter can move the whole track into an easier key first.
Load the file and drag the tempo slider - the browser time-stretches playback in real time, so a solo at 60% speed stays in the original key. This is the standard practice workflow: start where you can play every note cleanly (often 50-75%), loop the passage, and raise the speed a few percent at a time.
Time-stretching keeps pitch fixed by cutting the audio into tiny overlapping grains and re-spacing them, which introduces mild artifacts - a slight phasiness and softened transients. Between about 75% and 125% they are hard to hear on full mixes; at 25% or 200% they are audible but the notes remain clear, which is what matters for transcription and practice.
Not from this page - browsers expose pitch-preserving stretch for live playback only, with no offline render API, so any site offering "free time-stretch downloads" is processing your file on its servers. Everything here stays on your device. If a downloadable file matters more than constant pitch, the audio speed changer exports a resampled (pitch-following) WAV.
Slow enough that you make no mistakes - speed with errors just rehearses the errors. A common progression is 60% until clean, then 70, 80, 90, 100 in separate passes, dropping back one step whenever accuracy slips. Find the song's original tempo with the BPM counter so you know what each percentage means in beats per minute.
Generate single tones with precise frequency control. Perfect for quick audio testing and tuning.
Play multiple frequencies simultaneously with independent volume and panning controls.
Create linear or exponential frequency sweeps for speaker testing and room acoustics analysis.
Generate binaural beats for meditation, focus, and relaxation. Requires headphones for proper effect.
Generate telephone dial pad tones (Dual Tone Multi Frequency). Interactive touch-tone dial pad.
Professional metronome with tap tempo, time signatures, subdivisions, and tempo trainer for musicians.
Tap along to any song to find its tempo in beats per minute. Includes tempo markings reference.
Hear major, minor, diminished, and seventh chords in every key. Block chords or arpeggios.
Hear classic progressions like I-V-vi-IV and 12-bar blues in any key at any tempo.
Free browser piano with 3 octaves, note names, and computer keyboard support.
Generate white, pink, and brown noise for sleep, focus, tinnitus relief, and speaker burn-in.
Reference tuning notes for guitar, bass, ukulele, violin, cello, and more at concert pitch (A440).
Test your subwoofer with a 60-second frequency sweep (150Hz-1Hz) and individual bass test tones.
Test your hearing range from 8kHz to 20kHz. Find your hearing age and compare with averages.
Ancient healing tones including 528Hz (DNA repair). For meditation, chakra activation, and spiritual healing.
Test stereo balance with panning control and left/right channel testing. Perfect for speaker setup.
Check speaker wiring polarity by comparing in-phase and out-of-phase test signals.
Measure your Bluetooth or system audio delay in milliseconds with a click-and-flash sync test.
Real-time frequency analysis of your microphone input with a live log-frequency display.
Measure approximate sound levels with your microphone - live dB with min/avg/max tracking.
Check your microphone in seconds: live waveform, level meter, and record-and-playback check.
Learn to recognize musical intervals by ear with quiz mode, score tracking, and song mnemonics.
Chromatic pitch pipe with all 12 notes across 3 octaves. Perfect for singers, choirs, and a cappella groups.
Experience the auditory illusion of an infinitely ascending or descending tone. Mind-bending psychoacoustic phenomenon.
Can you hear the mosquito tone? High-frequency test (15-20kHz) that only young people can hear. Find your hearing age!
Create relaxing ambient soundscapes with singing bowls, nature sounds, and binaural beats.
Three sound modes to clean a muffled speaker: 165 Hz water eject, dust-shaking sweeps, and vibration.
Push water out of a wet phone or watch speaker with a pulsed 165 Hz tone - the same method Apple Watch uses.
Adjustable high-frequency whistle (8-22 kHz) for dog training - clearly audible to dogs, silent to most adults.
Rhythmic pulsed tones across delta to gamma ranges. Stronger than binaural beats and works without headphones.
Name 12 random notes with no reference tone and find out if you have absolute pitch or great pitch memory.
Sing your lowest and highest notes and get your range plus voice type - bass to soprano. Mic-based, nothing uploaded.
Find the highest frequency you can hear (8-20 kHz) and see how old your ears test. Takes one minute.
Instant karaoke via center-channel cancellation - free, unlimited, and processed locally.
Record from your microphone and download as WAV - no signup, nothing uploaded.
Normalize any file to a LUFS target with true-peak protection instead of silent clipping.
16-step beat maker with synthesized 808-style drums, swing, and shareable pattern links.
Drop a file and get integrated LUFS, true peak, RMS, and a waveform - measured locally, nothing uploaded.
Microphone tuner with a cents needle - play any note on any instrument and tune to ±5 cents.
Five-minute headphone checkup: channels, wiring polarity, bass and treble reach, and driver distortion.
Send noise to each 5.1 channel - fronts, center, surrounds, and subwoofer - and catch swapped or dead speakers.