Speed up or slow down your video while keeping the audio's pitch natural. Works instantly in your browser — no upload, no account needed.
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Choose Video FileMP4, WebM, MOV · Max 100MB
Audio pitch stays natural — no chipmunk or deep-voice effect.
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This tool changes the playback speed of a video — speeding it up or slowing it down — while keeping the audio's pitch natural, rather than making voices sound chipmunk-like when sped up or distorted when slowed down.
Processing happens entirely in your browser using a built-in video processing engine — your video is never uploaded to a server. The first time you use any of our video tools, there's a one-time download of this processing engine (around 30MB), cached afterward for instant use. Speed changes require re-encoding, so processing time depends on your video's length.
Unlike our Audio Speed Changer, which changes speed by resampling (and therefore also changes pitch), this tool processes video and audio separately: the video frames are sped up or slowed down by adjusting their timing, while the audio is processed with a time-stretching technique that changes tempo without affecting pitch. This means a sped-up video doesn't produce high-pitched "chipmunk" voices, and a slowed-down video doesn't produce a deep, distorted sound — speech and music sound natural at the new speed.
For time-lapses, higher multipliers (2x-4x or more) work well for footage with gradual change over time. For slow-motion, 0.5x is a common choice, though note that slowing down video doesn't add new frames — it simply plays existing frames over a longer time, which can look less smooth than footage recorded specifically for slow motion at a high frame rate.
The ideal speed multiplier for a time-lapse depends on how long the original footage is and how long you want the final result to be. A useful way to think about it: a 10-minute recording sped up 10x becomes a 1-minute clip, while the same recording sped up 60x becomes a 10-second clip. For footage of gradual processes — clouds moving, a plant growing over days (captured as a long recording), light changing throughout a day — higher multipliers tend to work better, since the interesting changes happen slowly relative to the recording length. For footage with more activity — a busy street, a cooking process — a more moderate multiplier keeps enough detail visible to follow what's happening, while still compressing the overall time meaningfully.
True smooth slow motion — the kind seen in sports broadcasts or nature documentaries — is achieved by recording at a high frame rate in the first place (for example, recording at 120 or 240 frames per second and then playing back at normal speed, which naturally stretches the action). Slowing down footage that was recorded at a standard frame rate (commonly 24-30fps) doesn't add any new information between the existing frames — it just holds each frame for longer. At moderate slowdown (0.5x-0.75x), this is often not very noticeable, especially for footage without fast motion. At more extreme slowdown, or for footage with fast-moving subjects, the lack of additional frames becomes more apparent as a slightly choppy or stuttering quality, since what would ideally be smooth motion is instead a sequence of held frames played back more slowly.
If you only need to trim the video first, use Video Trimmer. To convert the result to a GIF, see Video to GIF.
No, audio is processed with a time-stretching technique that adjusts tempo without changing pitch, so speech and music sound natural at the new speed.
Typically from 0.25x (quarter speed) to 4x (quadruple speed), suitable for both slow-motion and time-lapse effects.
Not necessarily — slowing down existing footage plays the same frames over a longer time, which can look less smooth than footage recorded at a high frame rate specifically for slow motion.
Files up to 100MB are supported. Larger or longer videos take proportionally longer to process.
No, processing happens entirely within your browser.