Online Voice & Speed Changer

Create Sped-Up Nightcore remixes, Slowed & Reverb Lofi edits, or fun pitch-shifted voices in a few clicks. Two independent sliders for pitch and tempo, with presets for the hottest TikTok styles.

Audio Configuration
Select a file and adjust the settings below.
1x
0.5x (Slow)1.0x (Original)2.0x (Fast)
0 semitones
-12 (Low / Male)0 (Original)+12 (High / Female / Chipmunk)

About this online voice and speed changer

Nightcore and Slowed & Reverb are two remix styles going viral on TikTok and YouTube. Nightcore bumps tempo +25% and pitch +4 semitones for an energetic anime feel; Slowed & Reverb cuts tempo -15%, drops pitch -3 semitones, and adds aecho reverb for a dreamy late-night Lofi mood.

OneAudio Changer keeps pitch and tempo fully independent via FFmpeg's asetrate + atempo pair — unlike simple playback speed changes that warp both. You can speed up a track while keeping pitch the same, or swap voice gender (male ↔ female ↔ chipmunk) without touching the rhythm.

  • Independent pitch from -12 to +12 semitones (one octave either way)
  • Speed from 0.5× to 2.0× without warping vocals
  • One-click Nightcore preset: +1.25× speed + 4 semitones
  • Slowed & Reverb preset: 0.85× speed − 3 semitones + aecho
  • Auto-chains multiple atempo filters when ratio falls outside 0.5-2.0
  • 192kbps MP3 output, stereo preserved

Make Nightcore / Slowed-Reverb remixes online

  1. 1

    Upload an MP3 or WAV

    Drag and drop the source track (vocal, instrumental, or full mix). Any popular audio format up to 200MB works.

  2. 2

    Pick a preset or tweak by hand

    Click "Nightcore" or "Slowed & Reverb" for a one-click remix. For more control, drag the pitch and speed sliders yourself.

  3. 3

    Render and download the remix

    Click Apply Changes. In 15-30 seconds, the remixed MP3 is ready. Download and post to TikTok or Reels immediately.

Common uses of pitch / tempo shifting

Nightcore remixes for TikTok
Turn a current hit into a Sped-Up 15-30s clip — ideal for the trending short-form video format.
Slowed & Reverb for mood playlists
Convert a ballad into a somber Lofi version to use as background for vlogs or late-night playlists.
Funny voice effects for video
Pitch +12 for a chipmunk voice, -12 for a ghostly tone — instant meme fodder for Reels.
Practice singing in a different key
Drop pitch 1-2 semitones when the original key is too high for your range, to sing along comfortably.

Frequently asked questions about voice and speed changing

What's the difference between pitch and speed?
Pitch is how high/low it sounds. Speed is how fast it plays. YouTube's speed control changes both at once. OneAudio keeps them independent — speed up without raising pitch, or vice versa.
What's a semitone? What does -12 mean?
A semitone is the smallest Western music step — 12 semitones make an octave. Dropping 12 semitones = one full octave down (female → low male). Raising 12 = one octave up (adult → chipmunk).
Why does the pitched voice sound unnatural or metallic?
Because FFmpeg uses a simple rescaling algorithm, not pro-grade time-stretching like Melodyne. ±3 to ±6 semitones sound natural; ±12 takes on the classic "chipmunk" artifact.
Can I use 0.3× speed?
FFmpeg's atempo only accepts 0.5-2.0 per pass. OneAudio auto-chains filters (0.5 × 0.6 = 0.3) if you drag outside the range, but quality degrades with each chain.
What does Reverb do?
Reverb adds a 300ms tail for a "roomy" feel — a core element of the Slowed & Reverb mood. Keep it on for Lofi, off for Nightcore.
Any way to get robot / auto-tune vocals?
Not yet. The Changer only does basic pitch/speed/reverb. Auto-tune needs formant-preserving pitch correction — try Reaper + GSnap if you need pro-level.