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Speed up or slow down a video

Make a video play faster or slower, from 0.25× to 4×, with its sound kept in sync at the same pitch, at a changed pitch or muted; the picture is retimed in your browser and never uploaded.

Drop a videoMP4, MOV, WebM, MKV, AVI · up to 500 MB and 10 min free
Choose video
Runs in your browser · no uploadHow it works

How to use Change video speed

  1. 1

    Drop the video

    Add one MP4, MOV, WebM, MKV or AVI file of up to 500 MB and 10 minutes; its resolution, frame rate and codecs show under the player.

  2. 2

    Set the speed

    Choose 0.5×, 0.75×, 1.25×, 1.5× or 2×, or anything from 0.25× to 4× with the slider or the exact field. The player switches to that speed at once.

  3. 3

    Decide on the sound

    Keep pitch leaves voices natural, Change pitch lets them rise or drop with the speed, and Mute leaves the new video silent.

  4. 4

    Save it

    Press Change speed. Most videos are ready in seconds because the picture is copied rather than re-encoded; then download name-2x.mp4.

Limits and Pro

One video at a time, up to 500 MB and 10 minutes long, at 0.25× to 4×, with no watermark.

Pro handles videos of up to 4 GB and 10 hours. See Pro

About Change video speed

Change video speed writes a new copy of a video that plays faster or slower, with the sound adjusted to match. The picture is not re-encoded. Each compressed frame is copied as it is and only its timestamp changes, which ffmpeg does with its itsscale option, so quality is untouched and a 10-minute clip takes seconds rather than minutes. The catch is that the frame rate scales with the speed: a 30 fps clip at 2× plays at 60 fps, and at 0.5× at 15 fps. When a speed-up would pass 120 fps, a 60 fps phone clip at 4× for instance, the video is re-encoded at 60 fps instead, with WebCodecs where the browser has it, because many phones and players stutter on anything faster.

The sound is decoded, stretched by exactly the same factor and encoded again as AAC at 160 kbps, or Opus for WebM, so speech stays in sync with lips. Keep pitch uses ffmpeg's atempo filter; Change pitch replays the samples at a new rate, like a film projector running fast or slow.

Common jobs: trimming a screen recording or tutorial down to a platform's time limit, a 2× time-lapse of a drawing or a build, a 0.75× replay of a dance move, or slowing a sports clip to study a swing. The file keeps its container when it can (MP4, MOV, WebM and MKV), while AVI, WMV and other older formats come back as MP4. Only the first video and audio tracks are written; subtitles and extra language tracks are dropped.

Privacy

The video is read from your disk and retimed in this tab by ffmpeg.wasm in a Web Worker; your browser's WebCodecs encoder is used only when a speed-up has to be re-encoded. Nothing is uploaded or kept. The 31 MB engine comes from jsDelivr the first time and then stays cached.

Features

No re-encoding

The picture is copied with new timestamps, so even long clips finish in seconds.

Sound in sync

Audio is stretched by the same factor, at its own pitch or a shifted one.

Live preview

The player runs at your chosen speed before you save anything.

Keeps the container

MP4, MOV, WebM and MKV return in their own format; older ones as MP4.

Change video speed: frequently asked questions

Does changing the speed lower the video quality?
Usually not at all. For most speeds the compressed frames are copied byte for byte and only their timing changes, so the picture is identical to the original. Only the sound is encoded again, at 160 kbps. The exceptions are a speed-up that would play above 120 fps and a format MP4 can't hold; then the picture is re-encoded at high quality, and the page says so before you start.
Why does my sped-up video show 60 fps?
Because every frame is kept. A 30 fps clip played twice as fast shows 60 frames each second, which is smoother than dropping half of them and needs no re-encoding. Phones, browsers and editors play 60 fps without trouble. Above 120 fps, which a 60 fps clip reaches at more than 2×, the tool re-encodes at 60 fps and skips frames so the file plays well everywhere.
Can I keep the voices sounding normal?
Yes. Keep pitch is the default sound option: the audio is time-stretched with ffmpeg's atempo filter, so people talk faster or slower in their own voice. Change pitch gives the chipmunk effect when sped up and a deep, dragging voice when slowed down. Mute writes the video with no audio track at all, which suits time-lapses and clips you'll set to music later.
How do I make a video 2 times faster?
Drop the video, tap the 2× chip and press Change speed. The preview starts playing at double speed as soon as you pick it, so you can check the result first. The new file is half as long, has -2x added before the extension, and keeps the original's format whenever that format can carry the picture unchanged.
Can I speed up only part of a video?
Not in one go: the whole file gets the same speed. To change one section, cut it out with the Video trimmer, change its speed here, and join the pieces in an editor. For slow motion below 0.25×, or smoother slow motion with computed in-between frames, use the slow motion page, which runs on this same engine.

Other tasks with this tool

Related tools

All video & audio tools

Video trimmer

Cut the start and end of a video precisely

Change audio speed

Change the tempo of audio, with or without the pitch

Video compressor

Make videos smaller for email, WhatsApp and Discord

Video to GIF

Turn video clips into looping GIFs

Mute video

Take out, turn down or silence part of a video's sound