Slow a song to 25% to learn the solo, or speed it to 200% to skim a lecture - with the pitch held steady, or dropping like a slowed record. Local playback and export; nothing uploads.
Drop an audio file here, or click to choose
MP3, WAV, AAC/M4A, OGG - stays on your device
Preserve pitch on is the practice mode: the solo stays in its key while you slow it to 50-75%, loop it in the player, and creep the speed back up as your fingers catch on. Find the song's tempo first with the BPM counter and drill against the metronome. Preserve pitch off is the tape/vinyl mode - pitch drops with speed, which is the entire "slowed + reverb" aesthetic and also how you check a mix for surprises at other keys. Trim the result to length with the audio trimmer.
Load the file, keep "Preserve pitch" on, and drag the speed slider down - the browser time-stretches the audio so a 70% speed guitar solo stays in the original key. This is the practice-tool mode: musicians learning fast passages typically work at 50-75% and step back up.
Slowing audio with pitch following (preserve pitch off), usually to 75-85% - the pitch drops with the tempo like a slowed record, giving the deep, dreamy character of the genre. Add reverb in any editor afterwards. This tool exports exactly that vinyl-style slowdown as WAV.
The two modes use different machinery. Pitch-following speed change is pure resampling, which browsers can render to a file. Pitch-preserving playback uses the media element's built-in time-stretcher, which browsers expose for playback only - there is no offline render API for it. So: practice with either mode live, export the resampled (vinyl-style) version.
Resampling (pitch-following) is essentially lossless in quality terms - it is the same math as playing a record at a different speed. Pitch-preserving stretch introduces mild artifacts that grow with distance from 100% - transient smearing and slight phasiness, usually unnoticeable between 75% and 125% and audible at the extremes. For practice they are irrelevant.
No - decoding, playback, and export all run locally in your browser. Nothing is sent anywhere, and the page works offline once loaded.
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.
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.
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.