Is this video speed changer free?
Yes. This video speed changer is free with no signup or watermark, and it runs entirely in your browser.
Does it upload my video?
No. The speed change and MP4 export run locally in your browser, so your video stays on your device.
Can I use a custom speed?
Yes. The tool offers presets such as 0.5x and 2x and also lets you type a custom multiplier.
Does it keep the audio?
Yes. The output MP4 keeps the audio track when possible, with pitch compensation so the speech sounds natural at the new speed.
What format does it export?
The speed-adjusted video is exported as an MP4 that plays in browsers, social apps, and most media players.
How do I speed up a video?
Open it, pick a speed, and export. Both the frames and the audio are re-timed in your browser, and the audio pitch is preserved so the voices still sound natural.
Does speeding up the video make the voices sound higher?
No. The audio is time-stretched rather than resampled, so a lecture at 1.5x still sounds like the same person. Simply playing a file faster is what raises the pitch; this does not do that.
Will slowing down give me smooth slow motion?
No. Slowing down holds each existing frame for longer rather than creating new ones, so fast motion looks juddery. True slow motion requires footage shot at a high frame rate.
Does changing the speed change the file size?
Speeding up does: a shorter video is fewer frames to encode. A 60-minute talk at 1.5x is 40 minutes of video and lands proportionally smaller.
What speed is best for a lecture or a talk?
1.25x or 1.5x. Comprehension falls off sharply past 2x, and since the content is the same length either way, pushing further usually costs more than it saves.