Speed · 3 min read

How to speed up a video on Android

Fast motion fixes the most common problem in phone footage: too much of it. Speeding a clip up turns a slow walk into comedy, a long cook into a time-lapse, and a rambling take into something people finish watching. Here's how to do it free on your phone — and how to speed up only the dull stretch.

The quick answer

Install Reverse Movie FX (free, 50M+ downloads, 4.5★), tap Slow Mo/Fast Mo on the home screen, pick your clip, and drag a bar up on the timeline. Up is faster, all the way to 4×. Tap Save and the sped-up clip lands in your gallery. Detail below.

Step-by-step: make a fast motion video

1. Install the app. Get Reverse Movie FX from Google Play. Free, no account.
2. Open Slow Mo/Fast Mo. It's the third button on the home screen, under Reverse Video and Reverse Song Challenge. Reversing the clip first is optional — the speed editor stands on its own.
3. Pick your video. Anything in your gallery works.
4. Drag a bar up. The timeline shows your clip as speed bars, with normal speed in the middle. Drag up toward 4× to compress that stretch of the clip.
5. Save. The app re-renders and writes a normal video file to your gallery.

Speed up only the boring part

Most free apps apply one speed to the whole file, which is rarely what you want — the interesting three seconds get rushed along with everything else. Reverse Movie FX splits the timeline into segments that each carry their own speed.

Add a speed point where the dull stretch begins, push that segment to 3× or 4×, and leave the payoff at normal speed. The walk to the table races by, the trick lands in real time. Drag the divider to adjust exactly where the speed-up starts and ends, and tap the × on a divider to merge segments back.

Segments have a floor of half a second — split any finer and the app will tell you the segment would be too short.

The one-slider shortcut

If the whole clip should run at one speed, you don't need the segment editor at all. The Reversing options dialog — the one that appears when you reverse a video — carries its own speed slider from 0.25× to 4.00×. Set it there, pick your output mode and render once. Use the Speed Editor when different parts of the clip need different speeds; use this slider when they don't.

Fast motion vs time-lapse — which do you want?

A time-lapse is captured that way: the camera records one frame every few seconds over minutes or hours. Fast motion takes video you already shot and plays it faster. If the clip is already on your phone, fast motion is the only option available to you — and at 4× a two-minute clip becomes a punchy thirty seconds, which is the right length for Reels or Shorts anyway.

For anything longer than a few minutes, speeding up won't be enough on its own; trim first, then speed up what's left.

What happens to the audio?

It's re-timed with the picture, so voices rise in pitch as the clip speeds up — which is either the joke or the problem, depending on your video. If it's the problem, drop one of the app's music tracks over the top instead; the reverse video with music guide walks through the audio choices.

Is there a watermark?

No. Sped-up clips save as clean files to your gallery, with no watermark and no export paywall. The free version is ad-supported; Pro removes the ads.

What about on iPhone?

The Speed Editor is Android only right now. The iOS version of Reverse Movie FX handles reversing, music and loop modes, but not speed. iPhone's Photos app can't speed up an ordinary video either, so you'd need a separate iOS editor for this one.