StudioWavePro — Online Audio Editor with 48+ Studio Tools

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StudioWavePro’s Speed tool changes playback speed in two distinct modes. "Keep pitch" uses time-stretching (the SoundTouch algorithm) so a song slowed to 0.75× still plays in the same key — this is what musicians want for practice and what podcast listeners want for faster speech. "Change pitch" works like a turntable or tape machine: speeding up raises the pitch, slowing down lowers it, and the panel shows exactly how many semitones the pitch moves.

The speed slider runs from 0.25× (four times slower) to 4× (four times faster) in 0.05 steps, with one-click presets at 0.5×, 0.75×, 1.25×, 1.5× and 2×. The panel always shows the new duration before you commit, and the preview plays the actual processed audio — in keep-pitch mode it renders the first 5 seconds so feedback stays instant even on long files.

When to use

Slow a guitar solo or riff to 0.5× without changing key, to learn it note by note.
Speed up a lecture, interview, or podcast to 1.5×–2× for faster listening.
Slow down dictation or language-learning audio to catch every word.
Create slowed + reverb or sped-up "nightcore" style edits (use Change pitch mode).
Fit a voiceover or jingle into an exact time slot by nudging speed a few percent.
Get the vinyl/tape effect where pitch drops as the track slows.

How to use

Click "Open Speed" below to launch the editor.
Drop in any audio file — MP3, WAV, OGG, M4A and FLAC are all supported.
Choose a mode: "Keep pitch" (tempo changes, key stays the same) or "Change pitch" (vinyl-style, pitch follows speed).
Set the speed with the slider (0.25×–4×) or a preset button. The panel shows the new duration — and in Change pitch mode, the semitone shift.
Press "Play preview" to hear the result, then click "Apply Speed Change" and download as WAV or MP3.

Tips

For learning music by ear, 0.5×–0.75× in Keep pitch mode is the sweet spot — slow enough to hear detail, fast enough to keep the feel.
Time-stretching at extreme settings (below 0.5× or above 2×) introduces audible artifacts in any tool. If the result sounds watery, try a less extreme rate.
Keep-pitch previews use the first 5 seconds of the track so the slider feels instant; the full track is processed when you click Apply.
Want to change pitch without changing speed? That’s the Pitch Shift tool — the exact mirror of this one.
In Change pitch mode, doubling the speed raises pitch exactly 12 semitones (one octave); halving lowers it one octave. The panel does this math for you.

Frequently asked questions

How do I slow down a song without changing the pitch?: Open the Speed tool, select "Keep pitch" mode, set the slider below 1× (0.75× or 0.5× are the common picks), preview, then apply and download. The track plays slower but stays in the same musical key.
How do I speed up an MP3 without it sounding like chipmunks?: Use "Keep pitch" mode. It time-stretches the audio so voices keep their natural pitch at any speed. The chipmunk effect only happens in "Change pitch" mode, where pitch follows speed — which you can also use deliberately.
What speed range is supported?: 0.25× to 4× in steps of 0.05, in both modes. There are quick presets for 0.5×, 0.75×, 1.25×, 1.5× and 2×.
Does changing speed change the length of the file?: Yes — at 2× a 6-minute track becomes 3 minutes; at 0.5× it becomes 12. The panel shows the exact new duration before you apply.
How does this compare to the speed control in a media player?: A player changes speed live but never saves it. This tool renders a new audio file at the chosen speed that you download and keep — useful for sharing, importing into a DAW or video editor, or listening on devices without speed controls.
Which mode should I use for the "slowed + reverb" effect?: "Change pitch" mode around 0.8×–0.85× gives the characteristic deep, dragged sound, because pitch drops together with tempo. Slowing in Keep pitch mode just sounds like the same song played slower.
Why does my slowed audio have a slight underwater sound?: That’s a normal artifact of time-stretching, and it grows with how far you stretch. Below about 0.5× it becomes noticeable in any software. For transcription purposes it rarely matters; for music, stay within 0.6×–1.5× for the cleanest results.

StudioWavePro is a complete audio editor with 48+ studio-grade tools in one workspace. Trim, master, EQ, time-stretch, denoise, remove vocals, detect BPM and musical key, generate metronomes, and more. Editing tools

Audio Trimmer — crop a track to a selected region

Mute Section — silence a selected region

Reverse Audio — play the track backwards

Fade In/Out — ramp volume at start or end

Silence Trimmer — strip leading and trailing silence

Silence Gap Inserter — insert silence at a chosen position

Audio Looper — repeat a section N times

Audio Splitter — cut a track into multiple parts

Audio Merger — join multiple files end-to-end

Silence Splitter — auto-split at silent gaps

Crossfade Joiner — join clips with overlapping fades

Time and pitch

Speed Changer — speed up or slow down (with optional pitch preservation)

Pitch Shift — change pitch without changing tempo

Tempo Detector — estimate the BPM of a music track

Key Detector — estimate the musical key

Metronome Generator — create a click track at any BPM

Effects

Volume — make a track louder or quieter

Bass Boost — lift the low end

Treble Boost — lift the high end

Low Pass Filter — cut off high frequencies

High Pass Filter — cut off low frequencies (remove rumble)

Equalizer (3-band) — low / mid / high tonal shaping

Equalizer (10-band) — fine-grained tonal control

Echo — add repeating echoes / delay

Distortion — overdrive, fuzz, and lo-fi grit

Stereo Balance — shift the L/R center of a stereo mix

Stereo Widener — make stereo narrower or wider

Vocal Remover — karaoke (center-channel removal)

Hum Remover — strip 50/60 Hz mains hum

Mastering and analysis

Normalize — maximize volume without clipping

Compressor — even out loud and quiet parts

Loudness Meter — measure peak, RMS, and LUFS

Mono Converter — collapse stereo to mono

Channel Extractor — pull L, R, Mid, or Side

Sample Rate Converter — resample to 44.1, 48, or 96 kHz

Polarity Inverter — flip waveform for phase alignment

DC Offset Remover — center waveform around zero

Audio Visualizer — render an animated video from audio

StudioWavePro supports MP3, WAV, OGG, M4A, and FLAC files. Exports include WAV and MP3. This app requires JavaScript to run. Please enable JavaScript in your browser.