Video Tools
Video Trimmer — Cut Video to the Good Part
Cut a video down to the exact start and end you want — preview it in the page, set the times, and export just the good part, no upload needed.
Open toolChange Video Speed
A long process becomes a satisfying timelapse at 4x; a fast moment deserves slow motion at half speed. This tool retimes your video anywhere from quarter speed to four times speed — and, importantly, it pitch-corrects the audio while doing it, so a sped-up voice stays a voice instead of turning into a chipmunk, and a slowed voice doesn't slur. The whole job runs in your browser with the FFmpeg engine; nothing is uploaded. Remember that slow motion can't invent frames: slowing a 30 fps clip stretches the frames it has, which is exactly the classic slow-mo look.
Choose a file to begin — nothing is uploaded, everything happens on your device.
How to use this tool
- Choose the video.
- Pick the new speed — 2x for timelapse feel, 0.5x for slow motion.
- Keep pitch correction on so voices sound human (it is, by default).
- Click Change speed and download the retimed video.
Worked example
Slowing a 3-second clip to half speed stretched it to exactly 6 seconds in our test — and with pitch correction the voice deepened naturally instead of turning into a slur.
Frequently asked questions
How does pitch correction work?
Naively speeding up audio raises its pitch; slowing it lowers the pitch. The atempo filter instead time-stretches the sound the way podcast apps do — tempo changes, pitch stays. For extreme factors the tool chains the filter (two 2× steps for 4×) because a single step only covers 0.5×–2×.
Will slow motion look smooth?
It will look like classic slow motion: the existing frames play for longer. A 30 fps video slowed to 0.25× effectively shows 7.5 frames per second — dreamy but steppy. For buttery slow-mo, shoot at 60 or 120 fps first, then slow that down.
Does changing speed change the file size?
Roughly in proportion to the new length: a 4× version is about a quarter of the frames, a 0.5× version about double. The tool re-encodes at a good quality setting, so sizes are predictable rather than explosive.
Can I speed up only part of a video?
Not in this tool — the whole clip gets one speed. Trim the part you want with the Video Trimmer first, retime it here, and the rest of the original stays untouched.