Video Speed Changer

Upload your clip, choose a target speed multiplier, and the tool processes each frame. For slow-motion, it synthesizes new intermediate frames via optical flow so the result plays smoothly rather than looking choppy. For speed-up, it selects which frames to keep by analyzing motion between them, dropping the least informative ones rather than removing every Nth frame blindly.

The tool accepts MP4, MOV, AVI, and WebM. Resolution and frame rate of the source do not need to match any particular standard. A higher-quality source gives the optical flow algorithm more pixel data to work with, which results in cleaner interpolated frames in slow-motion mode.

File size limits depend on your account plan and are shown on the upload screen. Duration is the more relevant constraint for processing time: longer clips require the interpolation engine to synthesize more frames. Trimming your clip to the section you actually want to slow down before uploading will cut processing time considerably.

Processing time depends on clip duration, resolution, and whether Smooth Motion interpolation is active. Speed-up processing is faster because it selects from existing frames. Slow-motion with interpolation takes longer because new frames are generated for every gap. A one-minute 1080p clip at 0.5x speed typically finishes in a few minutes.

Uploaded clips are processed on secure servers solely to apply the speed change. They are not shared with third parties or used for training. After the output is ready and downloaded, your file is removed from processing storage. You retain full rights to the original footage and the re-timed output.

Output is delivered as MP4. The pixel dimensions match your source video exactly. Speed changes do not degrade visual quality because the frame selection and interpolation steps operate on the original frame data rather than a re-encoded intermediate. Audio is also pitched-corrected so voices and music stay at the right pitch after the speed change.

Yes. This tool re-times footage you supply; it does not add any licensing restrictions to the output. Copyright in the resulting clip belongs to whoever held rights to the original footage. If you are using licensed music or footage, your existing rights and obligations for that content still apply as they would with any editing tool.

No. Upload the clip, drag the speed slider to your target multiplier, toggle Smooth Motion on or off depending on whether you want interpolated frames, then click process. There are no timelines to manage or codec settings to configure. The same workflow works for a quick 2x speed-up or a detailed 0.25x slow-motion shot.

Yes. Once processing is complete, a player appears so you can watch the re-timed clip before downloading. Pay attention to the motion of fast-moving objects: if interpolated frames look slightly blurry at edges, that is the optical flow filling in motion it has to estimate. Turning off Smooth Motion and re-processing gives you frame selection only, without any synthesized frames.

Standard editors slow a video down by stretching existing frames, which produces a stuttering effect when you go below about 0.5x on 30fps footage. This tool instead generates new frames between the originals using optical flow, so motion stays fluid at any slow-motion multiplier. The Smooth Motion toggle is the key difference: at 0.25x on 30fps, a regular editor shows the same frame repeated four times, while this tool fills those gaps with synthesized motion.