Change Audio Speed & Pitch Online — Free Tool

Speed up, slow down, or re-pitch any audio free in your browser. Time-stretching keeps pitch natural; pitch-shifting keeps timing intact.

Speed vs. Pitch, Finally Explained

Picture a vinyl record. Spin it faster and two things happen at once: the music gets shorter and higher-pitched. Digital tools can split those two effects apart:

• Tempo change (time-stretching) alters duration only. Stretch a 3-minute song to 4 minutes and every note keeps its pitch. The classic use is learning fast solos or transcribing speech.
• Pitch shift alters musical pitch only. Raise a song two semitones and it plays in exactly the same time. The classic use is fitting a song to a singer's range.

Mixing the two up is the most common beginner mistake I see. Want the nightcore effect, faster and higher like sped-up vinyl? That's both at once, and the Nightcore Maker does it in one step.

Slow It Down Without the Chipmunk Effect

1. Open the Tempo Changer and load your audio. Any MP3 or WAV works. Processing stays local and private.
2. Set your speed. The tool runs from 25% to 200%. For transcription and practice, 50 to 75% stays surprisingly intelligible. For podcasts, 120 to 150% is the popular listen-faster zone.
3. Preview, then export. Time-stretching uses a phase vocoder under the hood. Moderate settings sound natural. At extremes you'll hear a slight shimmer or warble, especially on dense mixes.

A practical warning: slowing speech below about 60% smears the consonants. If you need it slower for study, go in two passes, say 80% then 80% again. Artifacts accumulate more gracefully that way. And if a sped-up podcast sounds chipmunky, that's a pitch problem, not a speed problem: nudge it down a semitone or two with the Pitch Shifter while keeping your faster tempo.

Change Pitch Without Changing Speed

1. Open the Pitch Shifter. Load the same file. The workflow mirrors the tempo tool.
2. Dial in semitones. One semitone is the step between adjacent piano keys. Karaoke singers most often need minus 1 to minus 3. A fun chipmunk effect starts around plus 5.
3. Listen for artifacts. Small shifts, plus or minus 3 semitones, are nearly transparent on most material. Push past plus or minus 6 and voices start sounding processed. Which is fine if that's the sound you're after.

Worth knowing: shifting a full mix and shifting an isolated vocal behave differently. If you've already split a song with the Stem Splitter, pitch-shifting just the vocal stem comes out cleaner than shifting the whole dense mix.

The Fun Stuff People Actually Use These For

• Nightcore: speed up 1.15× to 1.35× with pitch following along, the signature hyperpop-adjacent sound. One click in the Nightcore Maker. The classic setting is 1.25×.
• Slowed and reverb: drop to around 80% speed and wash it in reverb for that dreamy late-night feel. The Slowed + Reverb tool chains both in one pass.
• Practice slowdown: musicians loop hard passages at 70% with pitch intact, then creep back toward 100% as muscle memory builds.
• Podcast catch-up: 1.25× on talk content saves real time with barely any voice change. Past 1.5× most voices start sounding rushed.
• Key matching for mashups: pitch-shift two songs into the same key before layering them. Suddenly the blend works.

One honest note: extreme settings expose the math on both tools. Time-stretch past 2× or pitch-shift past an octave and things start sounding digital: smeared transients, warble, metallic edges. For moderate musical adjustments, though, browser DSP is genuinely excellent now. My rule of thumb: if the change serves the song, a better key, a learnable tempo, listeners never notice the processing. If the processing is the point, nightcore, chipmunk vocals, lean into the artifacts. They're part of the sound.

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