OneTaskBy Tim King · Updated
Slow Motion Player
Watch Any Video at 10% to 75% Speed
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How the Slow Motion Player works
This slow motion player plays any video at between 10% and 75% of normal speed, so you can see what happens too fast to follow. Choose a speed, press play and the clip loops until you stop it. Nothing is rendered or uploaded; your browser simply plays the file more slowly.
A tennis serve, a golf swing or a skateboard trick lasts well under a second. At full speed the eye sees a blur. Slowing the playback stretches that moment so you can follow the arm, the club or the board through each position.
How the slow motion player works
The browser's video player has a playback rate setting. The tool sets it to your chosen speed and turns on looping, so the clip repeats endlessly. Nothing is re-encoded, which is why the change is instant. To save a slowed copy as a new file, use the video speed changer.
| Speed | One second lasts | A 10-second clip takes |
|---|---|---|
| 0.75 | 1.3 s | 13 s |
| 0.5 | 2 s | 20 s |
| 0.33 | 3 s | 30 s |
| 0.25 | 4 s | 40 s |
| 0.2 | 5 s | 50 s |
| 0.1 | 10 s | 1 min 40 s |
Slow motion and frame rate
Slowing playback does not create new frames. A 30 fps clip at 0.25 speed shows each frame for about 133 ms, which is around 7 frames a second, so motion looks steppy. Footage shot in a phone's slow-motion mode at 120 or 240 fps slows far more smoothly. If the clip already plays slowly in your gallery app, it was saved with the slowdown built in.
Sound options
Keep corrects the pitch so voices and music sound at their normal pitch, just stretched. Browsers usually mute audio below about 25% because it becomes unintelligible. Natural lets the pitch fall, like a slowed tape, which suits impacts and engine noise. Mute removes the sound.
Tips and pitfalls
For one exact moment, step instead. Below 0.25, the frame by frame viewer is often clearer, as you control when each frame advances.
Loop a short section. Slowing a five-minute video to 0.1 takes 50 minutes to watch. Trim the clip first, or use the video A-B loop to repeat just the part you need.
How to read the result
The stats show the speed, the clip's real length, how long it takes to watch at that speed, how long one second of action lasts and the video's size.
FAQ
How do I play a video in slow motion?
Load the video, choose a speed such as 0.25 and press play in the player. The video plays at that fraction of normal speed and loops. Change the speed at any time; it takes effect immediately without restarting the clip.
Why does my slow motion look jerky?
Slowing playback stretches the frames that exist rather than adding new ones. A 30 fps phone clip at quarter speed only shows about 7 frames a second. For smoother results, film in the phone's slow-mo mode at 120 or 240 fps.
Can I save the video in slow motion?
Not with this player, which only changes how the file is played. To save a slowed-down copy, use the video speed changer, which renders a new file at the speed you choose, with the sound adjusted to match.
Is my video uploaded?
No. The video is played by your browser from your own device. Nothing is sent to a server, which also means large files start playing straight away with no upload wait or size limit.
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