mtools.lol

Video Speed Changer

Speed a video up or slow it down, with the sound kept at a natural pitch.

How it works

  1. 1Upload your video.
  2. 2Pick the speed and whether to keep the sound.
  3. 3Download the new MP4.

Features

  • From 0.25× (slow motion) to 4× (fast forward).
  • Sound is sped up or slowed down without chipmunk voices.
  • Or remove the sound completely.
  • Frame rate stays smooth when speeding up.

Frequently asked questions

Will slow motion look smooth?

Frames are shown longer, not invented, so very slow speeds can look choppy. 0.5× usually looks fine.

Why does the sound not sound high-pitched?

The tempo changes while the pitch is kept, so voices still sound natural.

Is there a file size limit?

Files up to 100 MB. Longer or larger videos may take up to a few minutes to process.