How to speed up a video (or slow it down), free and in any app

The free speed up video tool speeds a video up or slows it down in your browser. The file is made on your device, so nothing is uploaded, and there's no watermark and nothing to sign up for.

1. Choose a video (MP4, MOV, WebM or MKV) or a sound file (MP3, M4A or WAV).
2. Pick a speed: 0.5×, 0.75×, 1.25×, 1.5× and 2× are one tap away, or use the slider for anything from 0.25× to 4×. The preview plays at that speed.
3. Leave “Keep the voice's pitch” on. Turn it off only if you want a voice higher when it's faster and lower when it's slower.
4. Check the new length. If the video runs over 60 seconds, 90 seconds or 3 minutes and fitting it takes no more than 2×, one tap sets the speed that fits.
5. Download an MP4 for a video, or an MP3 for a sound file.

It takes up to 60 minutes of video at a time. The MP4's frame rate is never higher than the original's; why that matters for slow motion is further down. To slow a video down, it's the same steps with a speed under 1×.

All three apps have a Speed button in their cameras. Only TikTok's help describes changing the speed of a video you've already recorded or uploaded:

On TikTok, tap Add post (+), record or upload, and open the editing tools (Edit on the side panel; after an upload, tap Next first). Tap the clip or Edit at the bottom, then Speed, then Normal or Curve, and pick a speed. TikTok's help notes you can add one speed option to each clip, so split a clip first (Split, in the same editor) if you want two speeds in it.

For Reels and Shorts, set Speed before you record, or speed up the finished video first (with the free tool, CapCut or your phone's editor) and upload that. In Edits, Instagram's editing app, tap a layer of your project and choose Speed.

iPhone Photos app. Photos can't speed up an ordinary video. Its speed control slows down video captured at a high frame rate (above 30 fps, from iOS 18), and the options depend on the format you recorded in. For a video shot in Slo-mo, tap Edit and drag the bars under the frame viewer to choose which part plays slowly.

iMovie, Apple's free editing app, speeds up any clip:

1. Open a movie project, tap the clip in the timeline, then tap the Speed button. A yellow bar appears under the clip.
2. Drag the slider right to speed it up, or left to slow it down. The speed shows under the clip: 2x is twice as fast, 1/2x half.
3. For different speeds in one clip, drag the yellow range handles or tap Add to make ranges, and give each its own speed.
4. Reset puts the whole clip back to normal speed.

iMovie keeps the pitch of sped-up and slowed-down sound by default. Turn on “Speed changes pitch” in the project settings if you want a voice to go higher when faster and lower when slower.

Android (Google Photos). Open the video and tap Speed. Tap 2x or 4x to speed it up, or ½x or ¼x to slow it down. To change only part of it, touch and hold, then drag the trim handles. Tap Save to keep a copy. (Playback speed, under More, only changes how it plays, not the video.) Google Photos for iPhone has the same Speed choices under Edit, on iOS 16 or later.

CapCut. Tap the clip on the timeline, then Speed: Normal for one speed (CapCut says anything from 0.1x to 100x), or Curve for speed ramps, with presets such as Montage and Hero. Making a whole clip in CapCut is in how to make clips in CapCut.

There's no research-backed best speed. These are our rules of thumb from cutting talking clips, so trust your ears over them:

• 1.1× to 1.25× tightens a slow talker and often goes unnoticed. Good for talking heads, podcasts and lessons.
• 1.5× sounds quick. Fine for a screen recording or a recap; tiring for a story, and it can step on a joke's timing.
• 2× and up is for footage without speech you need to follow: B-roll, a process like cooking or building, a time-lapse.
• Under 1× is for action, a reaction or a detail. Speech slowed down drags, even with its pitch kept.

Speed sound up the simple way, like a tape played fast, and every sound in it gets higher. A voice at 1.25× comes out about 4 semitones higher, at 1.5× about 7, and at 2× a full octave (12 semitones), the chipmunk voice. Slow it down and the voice drops just as far.

Keeping the pitch fixes that. The sound is stretched or squeezed in time instead: short, overlapping pieces of it are laid down at the new pace, each picked to carry on smoothly from the last, so the voice runs faster but sounds like the same person. The free tool does this when “Keep the voice's pitch” is on, and so does iMovie by default.

Turn it off when the higher or lower voice is the point: a comedy bit, a deliberate chipmunk voice, or a slowed-down moment you want to sound deep and heavy.

A video is a run of still frames, often 30 a second. Speed it up to 2× and two seconds of footage play in one, so to stay at 30 frames a second, every other frame is dropped. At 4×, three in four go. Fast motion still looks smooth, because each frame that's left is new.

Slow motion is the opposite. At 0.5×, 30 frames a second of footage gives only 15 new frames for each second of playback, so frames repeat and the motion stutters. Smooth slow motion has to be filmed at a high frame rate:

• iPhone Slo-mo records 1080 HD at 240 fps on the back camera and 120 fps on the front, Apple says, with 4K at 120 fps on supported models (Settings, then Camera, then Record Slo-mo). Played back at 30 fps, 240 fps footage runs 8 times slower with a new frame every time.
• Optical flow in editors such as CapCut draws in-between frames, which CapCut says keeps big speed changes smooth. It's a guess at what happened between frames, so watch for warping around fast-moving edges.

The free tool keeps the frames you shot, with a frame rate no higher than the original's. It's best for speeding up, and for slowing down footage filmed at a high frame rate. To slow a video down elsewhere: TikTok and Shorts record at 0.3x and 0.5x, Google Photos has ½x and ¼x, and iPhone's Photos app slows down video shot at a high frame rate.

The maths is one line: the new length is the length divided by the speed, and the speed you need is the length divided by the length you want. 90 seconds at 1.5× is 60 seconds; a 4-minute video needs 1.34× to fit 3 minutes.

The lengths worth aiming for, from each app's help pages:

• YouTube Shorts can be up to 3 minutes long.
• Instagram takes reels of up to 20 minutes, but doesn't recommend reels over 3 minutes to people who don't follow you.
• TikTok takes uploads of up to 60 minutes, but its Creator Rewards Program only counts videos at least 1 minute long. Speeding a 70-second video to 1.25× makes it 56 seconds: too short to count.

How long a short video should be in the first place is a separate question, covered in how long a short video should be.

Speed shortens everything evenly, the voice included. Cutting shortens only what you cut, so the voice stays at its own pace. For speech, cutting usually sounds better:

• Cut the pauses. The free remove silence from video tool takes out the gaps between sentences automatically, so a talking video gets tighter without anyone sounding rushed. The settings are in how to remove silence from a video. For more pace, cut the pauses, then add a gentle 1.1×.
• Cut to the best part. No watchable speed fits a long video into a Short: 20 minutes into 3 would take about 6.7×. A clip of its best minute fits as it is.

Cutting clips from a long video is what Clyper does. Paste a YouTube link or upload a video, and it reads the transcript to find the best moments, cuts each one on whole sentences, frames it 9:16 on whoever's talking and captions every word. It doesn't change the speed or remove pauses inside a clip: if you want one tighter, run it through the speed up or remove silence tool afterwards. More in YouTube to Shorts.