Does this tool change the audio file itself?

Yes. Load a file, pick a speed and click Change Speed. The audio is decoded and processed in your browser, and you download a new WAV file. Your original file is not changed and is never uploaded.

Can I change the speed without changing the pitch?

Yes, that is the default. With Keep original pitch on, the tool time-stretches the audio with the SoundTouch algorithm (WSOLA), so a song at 0.75x stays in the same key. Turn it off to resample instead: the audio plays faster or slower like a tape, and the pitch rises or falls with the speed (2x is one octave up).

How is the new duration calculated?

New duration = original duration ÷ speed. At 2x speed a 60-minute file plays in 30 minutes. At 0.5x it plays in 120 minutes.

What speed values are supported?

Processing a file works from 0.25x to 4x. The duration calculator accepts 0.1x to 10x. Time-stretching sounds most natural between about 0.5x and 2x; beyond that, speech and music can sound choppy or smeared.

Why is the output a WAV file?

Browsers can decode MP3, M4A and most other formats but have no built-in MP3 encoder, so the tool writes an uncompressed 16-bit WAV with the same channel count as the source (stereo or mono), at the sample rate your browser decodes at (usually 48,000 or 44,100 Hz, shown when the file loads). WAV is larger than MP3; convert it afterwards if you need a smaller file. Files with more than two channels are reduced to stereo when you keep the pitch.

Can I use the duration calculator for video too?

Yes. The math is the same for any time-based media, so it works for videos, podcasts, lectures or any recording. File processing on this page is for audio files only.

Audio Speed Changer

Load an audio file, pick a speed from 0.25x to 4x, choose whether to keep the pitch, and download the faster or slower WAV. Nothing is uploaded.

Audio File

Optional. Load a file to change its speed. Nothing is uploaded.

Drop an audio file here or click to browse MP3, WAV, M4A, OGG, FLAC Keep original pitch (time-stretch)

Original Audio Duration

Hours

Minutes

Seconds

Playback Speed

Result

Enter a duration above to see the result.

Speed Reference Table

Enter a duration to populate the reference table.

Speed	Duration	Time Saved

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Summary

Load an audio file, pick a speed from 0.25x to 4x, choose whether to keep the pitch, and download the faster or slower WAV. Nothing is uploaded.

How it works

Drop an audio file (MP3, WAV, M4A, OGG or any format your browser can play) onto the file box.
Pick a speed from 0.25x to 4x, typed in or from the presets. The new duration and a table of common speeds update at once.
Leave Keep original pitch on to time-stretch with the SoundTouch algorithm, or turn it off to resample like a faster or slower tape, which also shifts the pitch.
Click Change Speed, listen to the result in the player and download it as a 16-bit WAV.
Without a file, type a duration in hours, minutes and seconds to see how long it lasts at any speed.

Use cases

Slow a song down to 0.75x without changing the key to learn a guitar or piano part.
Speed up a lecture or voice memo to 1.5x and keep a file you can play anywhere.
Make a slowed or sped-up version of a track with the pitch shifted, like a tape or vinyl effect.
Fit a voice-over or jingle to a fixed time slot by changing its tempo.
Estimate how long a podcast episode takes at 1.5x or 2x speed.
Compare duration savings across common playback speeds side by side.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu