Change Video Speed – 3 Simple Ways (PC, Online, Mobile)

Sometimes, adding special visual effects can bring your video to a whole new level. Even the most uncomplicated effects based on the change of the playback speed, fast-forwarding and Slow Motion (or “Slow-Mo”) can make a clip a lot more interesting to watch. For example, speeding up a part of your video can create a comedic effect, whereas Slow Motion is often used to give viewers the “time stood still” feel.

But speeding a video up or slowing it down can also be just a necessity: time-lapse clips just can’t be created without fast-forwarding them, and explanatory guides often contain the video slowdown effect so that viewers can have a closer look at specific things.

If you want to use these two effects, too, read our article and learn how to slow down videos or make videos fast on your PC, Mac, and mobile device, be it an iPhone or an Android phone.

Of course, film-makers use professional software to edit their footage. But you don’t need to be a pro to make a video in Slow Motion or speed it up if you’re using Movavi Video Editor. With this fully-featured video speed editor, anyone can be a great film editor. Read the instructions below to learn how to speed up a video or slow it down using the Movavi software.

As you can see, video-editing in Slow Motion or making a clip faster is comfortable with Movavi. There are lots of effects, presets, and stickers, too. Just give it a try!

Want to process a clip without installing a special slow-down or speed-up video editor on your computer? Do it online with Fastreel. It’s a free service that you can use to change the speed in short videos (smaller than 500 MB). It’s best if your file is already in the MP4 format; otherwise, you’ll have to convert it first.

Here is how to speed up a video online or make it slower with Fastreel.

1. Go to the Fastreel by Movavi service.
   Visit the Fastreel website
2. Upload your video by clicking on the Add Your File button.
3. In the Video Speed section in the left part of the screen, select the appropriate speed. You will be able to see the results in the preview window.
4. Mute the video if necessary by clicking the corresponding icon in the Audio section.
5. Save your video by clicking the Export Results button.

There are several options you can choose from to decrease or increase the speed of a video on an iPhone. Choose the appropriate one by clicking on one of the links below.

• Movavi Clips for Android
• iMovie for iPhone
• Photos app for iPhone
• Movavi App for iPhone

If you are an Android user, we suggest you try Movavi Clips, a great video slower and accelerator for mobile devices. Here is how to put a video in Slow Motion or speed it up in Movavi Clips.

1. Follow the link below to download the app on your phone.
   Download Movavi Clips on Google Play
   
   When the installation process is complete, launch the app on your mobile device.

2. Tap the Plus button at the bottom of the main screen, select the Video option, and locate your clip. Tap it and touch Start editing. Specify the aspect ratio of your video.

3. On the toolbar, tap the Speed icon. Move the slider to the right to accelerate the clip. To make the video slower, drag the slider to the left. Touch Apply and then tap the Save button. On the new screen, touch Save. The video is ready!

If you’re an iPhone user, you have access to one of the best free video editors on the market – iMovie. Many social media influencers admit to using it at the start of their career. The app is pre-installed on many devices. However, if you don’t have it on your iPhone, click the link below to get the application. Then, follow these instructions to change the speed of your video.

Get the iMovie app on the App Store

1. Touch the Plus sign to create a new project. Add the desired video to the app.

2. Select the video on the Timeline. Then tap the Speed icon to demonstrate the yellow Speed slider.

3. Drag the slider to the left to slow the video down and to the right to speed it up.

4. You can increase or decrease the speed of just a segment of the clip, and not the entire video. To do this, split the video into pieces by tapping the Timeline, then Split. Then select the part that you want to modify and change its speed as described above.

5. Tap Done when you’ve finished editing the clip.

Another default iPhone app for slow-motion editing is Photos. However, keep in mind that it can only edit videos shot in the Slo-Mo mode. This mode shoots the video in more frames per second than the regular Video mode. This makes the video take up more space on your device, but the main benefit is that you get a high-quality slow-motion video without buying a professional camera. One more intricacy with the Slo-Mo mode is that the default shooting pattern often makes the slow-motion start or end too early or too late, which spoils the effect. To change the speed settings and make the video perfect, follow thу instructions below:

1. Launch the Photos app and find the slo-mo video you want to edit.

2. Tap the Edit button at the top of the screen. On the Timeline, you’ll see the markers denoting the start and the end of the Slo-Mo effect. Drag them left or right to achieve the desired result.

3. When you’re satisfied with the result, tap Done.

Movavi App, a great fast-forward and slow-motion video app for iPhone, will allow you to easily tweak the speed of your clip. Just follow these steps.

1. Follow the link below to get the speed-up and slow-motion video maker app.
2. Download Movavi App on the App StoreWhen the installation is complete, launch the app.
3. Select a video you want to edit and tap Create video.
4. On the toolbar, find the Speed icon and tap it. A new window will open. Choose the new speed for your video by moving the scale below the clip. Apply the changes, then tap Export at the top right. Choose the video resolution and tap Save. Your video is ready! Now you know how to speed up a clip and how to make a video in Slow Motion on iPhone.

I’ve pulled more all-nighters in the editing room than I care to admit, and one thing’s become clear: messing with video speed up/slow down can be magic or mayhem. The first time I tried to give a scene that dreamy, cinematic slow-motion vibe, I was convinced it looked incredible. Then I hit play on the final export and realized it resembled a broken flipbook instead of a film. Since then, I’ve learned a few hard lessons about tweaking playback speed, and I’m here to share what actually works, so you don’t have to repeat my mistakes when you try to figure out how to slow down a video.

1. The stutter I didn’t see coming

When I slowed one video down by half, it started skipping like an old DVD. I later realized it didn’t have enough frames to fill the extra time.

My fix: I switched to an editor with optical flow, which generates missing frames between the originals. Now my slow-motion shots glide instead of jerk.

2. Ghosts in the frame

I had this issue when I stretched a clip just a bit too far, and suddenly my subject had a faint twin following behind – creepy and not at all intentional.

My fix: I use frame blending but only lightly. It softens motion transitions without smudging the entire shot.

3. When crisp became grainy

Speeding up a compressed video once turned my footage into a pixelated mess. Every detail broke apart, and no filter could hide it.

My fix: I only edit high-resolution source files now and always export in a high-bitrate format. Think of it like photography, start with the sharpest image possible.

4. When the soundtrack lost its place

I once sped up a clip in a project that had multiple audio tracks (dialogue, music, ambient noise) and suddenly nothing matched. The voiceover hit before the speaker opened their mouth, and the music cue landed miles off. It was chaos.

My fix: I learned to lock all the other tracks before adjusting the video speed. Then, once the edit’s done, I go back and re-sync everything manually. It takes a few extra minutes, but it saves hours of trying to untangle audio that’s wandered offbeat.

5. The chipmunk audio incident

I can still remember laughing (and then cringing) at a voiceover that turned helium-high when I doubled the playback speed.

My fix: I use pitch correction whenever I play with the video speed controller. If it still sounds off, I just mute it and add background music that fits the new tempo.

6. Flashing lights and flicker fiascos

It was not the best idea of mine to speed up a video with a cityscape because the changing streetlights turned into a full-on strobe show. Cool? Maybe. Watchable? Not really.

My fix: I apply exposure smoothing and color stabilization before exporting. It keeps lighting transitions natural instead of chaotic.

7. The glitch that came out of nowhere

Everything looked perfect in the preview, but when I exported the final cut, half the scene flickered like a broken light bulb. Frames skipped, colors shifted, it was a total nightmare. Turns out my GPU didn’t play nicely with the export settings.

My fix: When that happens, I turn off hardware acceleration and render the video in shorter chunks to catch any weirdness early. For big projects, I export to a lossless codec first, then compress later, it keeps quality high and glitches to a minimum.