Does changing speed keep the original pitch?

No. Pitch rises when you speed up and falls when you slow down. That is how atempo works in this engine. A pitch-preserving stretch belongs in a DAW. Use 1.25x or 1.5x on speech if chipmunks bother you. Avoid 2x unless you want the effect.

Will a 1.5x file still be understandable?

For lectures and podcasts, usually yes. Dense technical talks suffer more than story-style speech. 2x is a skim. 0.75x helps language study. Listen to a minute before you convert a two-hour course and delete the original tempo.

Will this speed changer work on iPhone or Android?

Yes, in Safari or Chrome, for ordinary music-length files. Long WAVs can exhaust phone memory. Convert those on a computer.

Why is there no 1x option?

1x would only re-encode to MP3 at the same tempo. That is a quality loss with no speed benefit. If you needed MP3 from WAV, use WAV to MP3. This page exists to change duration, not wrappers or containers.

Can I speed up a video file here?

No. This tool takes audio files only. Extract audio from the video first, then change speed on the MP3. If you needed the picture sped up too, that is a video editor job, not this audio filter.

Is it legal to speed up a podcast I downloaded?

A personal listening copy of a show you may keep is usually fine. Redistributing a sped-up commercial episode as your own can still be a copyright issue. Videozify does not store files and cannot check a licence or a feed contract.

Change Audio Speed Online

Drop a file here

Click to browse, or paste a file from the clipboard.

Choose file

A change audio speed tool time-stretches a track so it plays faster or slower and writes a new MP3. Pick 0.5x through 2x, drop a lecture or practice take, and download a file that fits the time you have.

How to change audio speed online

Drop an audio file onto the box above, or click Browse to choose it from disk.
Choose a speed. 0.5x or 0.75x slower, 1.25x, 1.5x, or 2x faster.
Press Change speed and wait until the progress bar reaches one hundred percent.
Download the MP3. Keep the original tempo file if you might need it later.

Why change audio speed instead of skipping in a player?

Change audio speed shortens or lengthens playback and bakes the new tempo into the file. Lecture apps offer 1.5x in-player. Downloaded MP3s on a car USB do not. Language drills need slower. Practice tracks need faster. You want a file that is already the new tempo, not a player setting you lose when you AirDrop.

This filter is ffmpeg atempo. Pitch follows speed. Chipmunks at 2x and molasses at 0.5x are expected. A pitch-preserving stretch is a different algorithm and not what this wasm build ships. If you needed nightcore without admitting it, you are in the right place. If you needed a slower violin that still sounds in tune, you need a DAW.

Output is 192kbps MP3. 1x is omitted so you do not pay a re-encode for no tempo change. Durations scale with the factor. A 10-minute talk at 1.5x is about 6 minutes 40 seconds.

Trim first if you only needed one chapter sped up. Speeding a two-hour dump in a phone tab is how memory dies.

Cut the chapter with the audio trimmer first. Voice Memos that are still M4A can convert to MP3 on the way in. This tool already writes MP3 out.

Audio speed change: what it does

	Input	Output
Files	MP3, WAV, M4A, FLAC…	MP3 192kbps
Speeds	Original tempo	0.5x, 0.75x, 1.25x, 1.5x, 2x
Pitch	Original	Follows speed
Length	Original duration	Duration divided by speed
Processing	Local	Local
Best for	Talks, drills, practice	Car USB, phone files

Change audio speed is a time-stretch tool that writes a faster or slower MP3 whose pitch follows the new tempo.

Why does pitch change with speed?

atempo resamples time. Faster means higher pitch. That is the classic tape-speed effect, not Rubber Band or Elastique. Shipping a pitch-locked mode that this core does not finish would be a fake control.

0.5x and 2x are the atempo limits without chaining filters. We do not offer 0.25x or 3x. Extreme factors sound worse than they save.

Speech survives 1.5x for most listeners. Music at 2x is a novelty. If the goal was a workout mix, listen once before you delete the original.

Should you trim before changing speed?

Yes, if only one section needed hurrying. Speed-changing dead air wastes CPU. Join chapters first only if every piece wants the same factor.

A quiet file sped up is still quiet. Boost after you hear the new tempo. Boosting first then speeding can clip differently.

Protected store files will not decode. Unprotected rips and recordings will. This is not a DRM tool.

Car USB sticks that only list MP3 are why the output is MP3 even when you dropped WAV. The tempo change already requires a decode. Writing WAV again would be a large file you still cannot play in the dash. Keep the WAV as the archive. Put the sped MP3 on the stick.

Frequently asked questions

Does changing speed keep the original pitch?: No. Pitch rises when you speed up and falls when you slow down. That is how atempo works in this engine. A pitch-preserving stretch belongs in a DAW. Use 1.25x or 1.5x on speech if chipmunks bother you. Avoid 2x unless you want the effect.
Will a 1.5x file still be understandable?: For lectures and podcasts, usually yes. Dense technical talks suffer more than story-style speech. 2x is a skim. 0.75x helps language study. Listen to a minute before you convert a two-hour course and delete the original tempo.
Will this speed changer work on iPhone or Android?: Yes, in Safari or Chrome, for ordinary music-length files. Long WAVs can exhaust phone memory. Convert those on a computer.
Why is there no 1x option?: 1x would only re-encode to MP3 at the same tempo. That is a quality loss with no speed benefit. If you needed MP3 from WAV, use WAV to MP3. This page exists to change duration, not wrappers or containers.
Can I speed up a video file here?: No. This tool takes audio files only. Extract audio from the video first, then change speed on the MP3. If you needed the picture sped up too, that is a video editor job, not this audio filter.
Is it legal to speed up a podcast I downloaded?: A personal listening copy of a show you may keep is usually fine. Redistributing a sped-up commercial episode as your own can still be a copyright issue. Videozify does not store files and cannot check a licence or a feed contract.