Speed up video faster or in slow motion, with the voice at the right pitch.
To speed up a video, choose the file, set a speed between 0.25x and 4x and click create. We show the new length first, keep the voice at its natural pitch and hand you an MP4 ready to post. It does slow motion and timelapse too. Free, with no sign-up and no watermark.
Free, no sign-upThis video has no sound, so only the picture changes speed.
Posting clips from this video? We find the best moments and deliver them captioned. Try it with my video
How to speed up a video
- 01
Choose the video
Drag an MP4, MOV, M4V, WebM or MKV file onto the area above, or tap to choose one. We show its resolution, frame rate and length.
- 02
Set the speed
Use the slider or a shortcut: 0.5x for slow motion, 1.25x, 1.5x, 2x, and 4x for a timelapse. The new length shows right away, and you decide what happens to the sound.
- 03
Create and download
Click create video and follow the progress. Watch the preview, check the report and download the MP4 with the speed in its file name.
How do I speed up a video without a chipmunk voice?
When a video simply plays faster, the sound speeds up with it and rises in pitch, like a tape at the wrong speed: the classic chipmunk voice. To avoid that, we treat the two separately. The sound is split into slices a few thousandths of a second long, which are fitted back together closer to each other and lined up by the shape of the wave. Speech gets faster, but the voice keeps its usual tone and pitch.
Up to 1.5x the change is barely noticeable, which is why lessons, tutorials and vlogs often run at 1.25x or 1.5x without anyone minding. At 2x speech is still clear but rushed. Beyond that, words start to run into each other, and for a timelapse it is usually better to drop the sound or replace it with music. If you want the comic high voice on purpose, pick the option where the pitch follows the speed.
| Speed | A 10 min video becomes | Common use |
|---|---|---|
| 0.5x | 20 min | Slow motion of one moment |
| 1.25x | 8 min | Snappier lessons and tutorials |
| 1.5x | 6 min 40 s | Vlogs and how-tos |
| 2x | 5 min | Recipes and long processes |
| 4x | 2 min 30 s | Timelapse of a build, trip or painting |
Will slow motion look smooth?
It depends on how many frames the camera recorded. A typical phone video has 30 frames per second. At 0.5x, every recorded second fills two seconds on screen, and there are only 30 pictures for 60 slots: each frame shows twice. At 0.25x, four times. We don't invent in-between frames, so motion takes on a slight step-by-step look that stays true to what was filmed.
Footage shot at 60, 120 or 240 frames per second is a different story. At 0.5x, a 120 fps video still delivers 60 real frames every second, with none repeated. That is how phones make true slow motion. The note under the slider tells you, before you create the file, whether frames will repeat and how many times.
What happens to quality when the speed changes?
To change the speed, every frame gets a new time, so the video is encoded again as H.264 in an MP4 that opens on any phone, editor and social network. We keep the original resolution and frame rate, up to 60 frames per second. When speeding up, we show only some of the frames: one in two at 2x, one in four at 4x. Motion stays smooth, just faster.
The sound comes out as AAC, the most widely accepted audio format in MP4. File size follows the new length: a video sped up to 2x usually gets smaller, and slow motion gets bigger. If you need an even smaller file for WhatsApp or email, run the result through the video compressor.
More than changing the speed. The best parts of your video, captioned.
Frequently asked questions
How do I speed up a video online for free?
Choose the video on this page, set the speed and click create video. The MP4 is ready to watch in the preview and download, with the new length in the report. It's free, with no sign-up, no watermark and no usage limit.
What are the fastest and slowest speeds?
From 0.25x, four times slower, up to 4x, four times faster, in steps of 0.05. For timelapses of several hours, like a whole sunset, the best result comes from your camera's own timelapse mode, which records few pictures per second from the start.
Will the voice sound high-pitched when I speed up a video?
No, as long as the option to keep the voice's pitch stays selected, which it is by default. Speech gets faster but keeps its usual tone. If you want the high voice on purpose, pick the option where the pitch follows the speed.
How do I make a slow motion video?
Pick 0.5x or lower. Each original frame shows more than once, because we don't invent new pictures. If the video was shot at 60, 120 or 240 frames per second, the slow motion uses those real frames and looks much smoother.
Can I speed up just one part of a video?
This tool changes the speed of the whole video. To speed up one part, cut it first with the video cutter, change its speed here and put the pieces back together in your editor.
Does it work with iPhone and vertical videos?
Yes. Vertical videos for Reels, TikTok and Shorts keep their orientation and resolution, and the result is an H.264 MP4. iPhone MOV files open on most current devices; if yours can't open an HEVC video, we tell you right away.
From a long video to ready clips. We find, cut and caption them.
Upload the video or paste a YouTube link. We find 4 to 60 scored clips, vertical and captioned, ready to review and download.
See the result on your own recording before adding a card.