How to speed up or slow down a video (without chipmunk voices)

Guides · Updated 14 October 2026 · By Tiago Santos

A long walk, a cooking clip, a screen recording of a slow install: most videos are better a little faster. Others need the opposite, like a dance move, a golf swing or a goal you want to see again slowly. Here’s what each speed does to the picture and the sound, and how to change it without uploading the video anywhere.

Which speed to pick

• 1.25× or 1.5×: talks, tutorials and vlogs. Still easy to follow, but the pauses stop dragging.
• 2×: screen recordings, cooking and DIY, anything where the steps matter more than the timing. A 3-minute clip becomes 1:30.
• 3× or 4×: a quick time-lapse of a walk, a drive or tidying a room. Voices at 4× are too fast to follow, so you may want to remove the sound.
• 0.5× or 0.75×: sport, dance and anything fast you want to see in detail.
• 0.25×: only for videos filmed in slow motion, see below.

Will voices sound like chipmunks?

Not if the tool keeps the pitch. Simply playing sound faster raises every voice, the way an old tape on fast forward does. Change video speed stretches or squeezes the sound in very short slices instead, so a voice at 2× sounds like the same person talking quickly, and at 0.5× like the same person talking slowly.

Why slow motion can look jerky

Slowing a video down doesn’t create new frames. A phone normally films 30 frames a second; at half speed, those same frames are spread over twice the time, so the video shows 15 a second and movement starts to look choppy. Below about 24 frames a second most people notice.

For smooth slow motion, film it in slow motion. iPhones and most Android phones have a Slo-mo mode that records 120 or 240 frames a second, and slowing those down to 0.5× or 0.25× still leaves 30 or more a second. The page tells you before you start when the result will be under 24 frames a second.

Speeding up has the opposite effect: at 4×, a 30 fps video would need 120 frames a second, more than phones and players show. Extra frames are left out so it plays at up to 60, which looks just as smooth.

Change the speed of a video, without uploading it

1. Open Change video speed and choose your MP4 or MOV, the kind phones and most cameras record.
2. Pick a speed from 0.25× to 4×. The page shows the new length straight away.
3. Tick “Remove the sound” if you don’t want it, change the speed, and play the result on the page before you save it.

The video is encoded again by your device’s own video encoder, in your browser. It isn’t sent to a server first, so a private clip stays on your phone or computer. On a computer it takes about as long as the video lasts; on a phone, longer. Keep the tab open until it finishes.

Only speed up part of a video

Change video speed works on the whole video. To speed up just the boring middle, cut the video into parts with Trim video, change the speed of that part, and join them back together with Merge videos.

Other things you might need

• Still too big to send after speeding it up? Compress video makes it smaller.
• Posting it on TikTok or Reels? Crop video makes it vertical.