Audio Speed Changer

How it works

How to change the speed of audio

Pick a speed, listen, save.

1
Add audio
Drop MP3, WAV, M4A, FLAC, OGG or video files onto the page.
2
Set the speed
Choose a preset like 1.25× or 0.75×, drag the slider or enter a target length. Use “Preview speed” to listen.
3
Save
Click “Change speed” and download the new files.

Why ToolCMB

Faster, slower, higher, deeper

Studio-style time-stretching in your browser.

Any speed

From quarter speed to four times faster in 0.05× steps.

Natural voices

Pitch-preserving time-stretching keeps speech clear — no chipmunk effect.

Pitch shift

Transpose songs up or down by semitones without changing the tempo — ideal for singing or playing along.

Exact length

Need a 30-second jingle or a song that matches your video? Enter the length, the speed is calculated.

Instant preview

Hear the new speed before processing.

Batch

Speed up a whole course or podcast series at once.

Private

Your audio never leaves your device.

Free

No watermark, no account, no limits.

Time-stretching vs. tape speed — what’s the difference?

With Keep the original pitch switched on, the audio is time-stretched: it gets faster or slower while voices and instruments stay in the same key. This is what podcast apps do at 1.5× and what musicians use to practise a fast solo at 75 %.

Switched off, the tool changes speed like a record player or tape: faster playback raises the pitch (the “nightcore” sound), slower playback lowers it (“slowed” edits). This keeps the audio perfectly smooth because nothing is stretched.

Pitch shift changes the key without changing the length — +2 semitones moves a song up a whole tone, −12 an octave down.

Common speeds

Speed	60 minutes becomes	Used for
0.5×	2 h	Transcribing, learning parts
0.75×	1 h 20 min	Practising music, language learning
1.25×	48 min	Podcasts, audiobooks
1.5×	40 min	Lectures, long podcasts
2×	30 min	Skimming recordings

Tips

Want to know the tempo of a song first? Use the BPM Calculator.
Remove pauses before speeding up speech with the Silence Remover.
Only need part of a song? Cut it with the Audio Cutter.
Changing the speed of a video’s sound? Extract it first or use the video tools such as Mute Video.

FAQ

Frequently asked questions

Can’t find your answer? Contact us — we reply quickly.

How do I speed up an MP3 without changing the pitch?

Add the file, choose a speed such as 1.25× or 1.5× and keep “Keep the original pitch” switched on. Then click “Change speed”.

How do I slow down a song?

Choose 0.75× or 0.5× (or drag the slider). With pitch preservation on, the song keeps its key; switch it off for a deeper, “slowed” sound.

Can I change the pitch without changing the speed?

Yes. Leave the speed at 1× and use the pitch slider to move up or down by up to 12 semitones.

How do I make audio exactly 30 seconds long?

Choose “Target length”, enter 0:30 and process. The speed is calculated for each file (between 0.25× and 4×).

Is my audio uploaded?

No. Processing happens in your browser; nothing leaves your device.

Which formats are supported?

MP3, WAV, M4A, AAC, FLAC, OGG, Opus and the soundtrack of videos. The result keeps the original format unless you choose another.