--- title: "Change Video Speed" description: "Speed up or slow down any video online. Retimes audio with the video, presets from 0.25x to 4x. No upload, no watermark, runs in your browser." url: https://findutils.com/media/video-speed-changer/ category: media --- # Change Video Speed Speed up or slow down any video online. Retimes audio with the video, presets from 0.25x to 4x. No upload, no watermark, runs in your browser. **Use this tool:** [Change Video Speed](https://findutils.com/media/video-speed-changer/) ## Programmatic access - Browser-only: this tool works on a file, the DOM, or a browser API and has no REST or MCP id. ## Why use our Video Speed Changer? Our video speed changer lets you speed up or slow down a video with one click. The audio is retimed along with the picture, so the result stays in sync. It works with MP4, WebM, MKV, and MOV files and runs entirely in your browser: each frame is drawn onto a canvas, the browser's MediaRecorder captures it, and Web Audio retimes the sound. The recorder works in real time, so the wait is about the length of the retimed clip and the export is a WebM file. Nothing is uploaded, so private footage stays on your device. The output carries no watermark, unlike most online video editors, and there are no usage limits. ## Tips for Best Results - Speeding a video up shortens it; slowing it down makes it longer. The duration readout shows the result before you export. - At high speeds the source may not have enough frames, so very fast output can look slightly choppy. - Slow-motion looks smoothest when the source was recorded at a high frame rate. - Audio pitch rises when you speed up and drops when you slow down — this is normal for a true speed change. - Trim the clip first with the Video Trimmer if you only want to retime part of it. ## Frequently Asked Questions ### How do I change the speed of a video online? Upload your video, pick a speed preset between 0.25x and 4x, then click Change Speed. The retimed file downloads with no watermark and no signup. ### Are my videos uploaded to a server? No. The clip is re-recorded in your browser and the video file never leaves your device. The page loads ad and analytics scripts as most sites do, and they never see your file. ### Does the audio stay in sync when I change speed? Yes. The audio track is retimed along with the video, so speech and sound stay aligned with the picture at the new speed. ### Why does the audio sound higher or lower after a speed change? Speeding a video up raises the audio pitch and slowing it down lowers it. This is the natural result of a true speed change, the same as playing a record faster or slower. ### Can I create slow-motion video? Yes. Choose 0.5x or 0.25x to slow the video down. Slow motion looks smoothest when the original was recorded at a high frame rate. ### Is there a watermark on the output? No. The output has no watermark and no branding. It is ready to upload or share immediately. ### What format is the output video? The retimed video is saved as a WebM file, which is widely supported by browsers and social platforms. You can convert it with the Video Format Converter if you need MP4. ### Is there a file size limit? Yes. The tool accepts videos up to 500 MB and rejects anything larger before reading it. Within the cap, the recording runs in real time, so the wait is about the length of the retimed clip. ## Related Tools - [Video Trimmer](https://findutils.com/media/video-trimmer/) - [Video Resizer](https://findutils.com/media/video-resizer/) - [Video Cropper](https://findutils.com/media/video-cropper/) - [Video Format Converter](https://findutils.com/media/video-format-converter/) - [Mute Video](https://findutils.com/media/mute-video/) - [Video to GIF Converter](https://findutils.com/media/video-to-gif/)