The fastest way depends on what you're starting with

Slow motion is easiest in the software you already have: Windows 11 comes with Photos, Mac has iMovie built in, and both iPhone and Android have native slow-motion tools. If you shot the video at normal speed and want to slow it down after, Photos or iMovie will do it in under a minute. If you need more control — changing the speed at different points in the video, or exporting at a specific frame rate — you'll want a dedicated editor like DaVinci Resolve (free) or Adobe Premiere Pro (paid subscription).

The choice matters because some tools lock you into their format, some require a subscription, and some will take hours to export a five-minute video depending on your computer's power. Start with what's already on your device, and move to something else only if it won't do what you need.

Key Takeaways

  • Windows Photos and Mac iMovie can slow down any video to half speed or slower in seconds, with no learning curve.
  • If you shot video on iPhone or Android at 60fps or higher, you can create slow motion directly in the camera app without editing software.
  • DaVinci Resolve is free and lets you change speed at different points in the same video, which the built-in tools cannot do.
  • Exporting (saving the final video) takes much longer than editing — expect 10 minutes to an hour depending on video length and your computer's processor.

Slowing down video in Windows Photos

Open the video in the Photos app (search "Photos" in the Start menu). Click the pencil icon at the top, then select "Edit" from the menu that appears. Look for the speed slider — it's usually in the toolbar at the bottom. Drag it left to slow the video down. You can preview the change before you save.

When you're done, click "Save a copy" at the top right. Photos will export the video to your Videos folder. The export takes a few minutes depending on how long the video is and how much you slowed it down. The original file stays untouched.

Photos has limits: you can only apply one speed to the whole video, and you can't slow it down to less than half the original speed. If you need finer control, move to DaVinci Resolve.

Slowing down video in Mac iMovie

Open iMovie and create a new project. Drag your video into the timeline at the bottom. Right-click the video clip and select "Show Clip Filter" — a panel will open on the right side. Look for "Speed" and drag the slider left to slow it down. You'll see the change in real time in the preview window.

When you're satisfied, go to File > Share > File. Choose your resolution (1080p is standard), and click Next. iMovie will export the video to your Downloads folder. The export can take 5 to 15 minutes depending on the video length.

Like Photos, iMovie applies one speed to the entire clip. If you need to slow down only part of the video, you'll need to split the clip first: right-click where you want the split, select "Split Clip," and then apply different speeds to each piece.

Creating slow motion on iPhone or Android

If you recorded the video at 60fps or higher (check your camera settings before you shoot), you can create slow motion directly in the camera app without any editing software.

On iPhone: Open the video in Photos, tap Edit, and look for the speed slider at the bottom of the screen. Drag it left to slow down the video. The slower you go, the more frames the phone has to work with, so 60fps video can go slower than 30fps video. Tap Done to save.

On Android: The process varies by phone model. On Samsung, open the video in the Gallery app, tap Edit, and look for a speed or playback option. On Google Pixel, open the video in Google Photos, tap Edit, and look for Tools > Speed. Drag the slider to slow it down. Tap Save to overwrite the original or Save a copy to keep both versions.

Using DaVinci Resolve for frame-by-frame speed control

DaVinci Resolve is free software that runs on Windows, Mac, and Linux. Download it from blackmagicdesign.com. It's more powerful than the built-in tools because you can change the speed at different points in the same video — slow down a jump, keep the landing at normal speed, then slow down the landing impact.

Open DaVinci Resolve and create a new project. Drag your video into the timeline. Right-click the clip and select "Retime Controls" > "Show Retime Controls." A panel appears above the clip with speed markers. Click where you want to change the speed, and drag the marker up or down. The video will slow down or speed up from that point forward until you add another marker.

When you're done, go to File > Export > Add to Render Queue. Choose your format (H.264 is standard for most uses), resolution, and frame rate. Click Start Render. The export can take 30 minutes to an hour or longer depending on your computer's processor and how much you slowed the video down. A faster processor cuts this time significantly.

Why export takes so long

When you slow a video down, the software has to create new frames between the original ones to fill the time. A video that's 30 seconds long at normal speed becomes 60 seconds long at half speed — the software is essentially rebuilding the entire file. This is why export time jumps dramatically when you slow a video to a quarter of its original speed.

Your computer's processor (CPU) does most of this work. A newer processor with more cores will export faster. If you're exporting a long video and your computer is old, plan to leave it running for several hours. You can usually close the software and use your computer for other things while it exports in the background.

Choosing a file format for your slowed-down video

When you export, the software asks what format to save in. For most uses, stick with MP4 (H.264 codec). It plays on any device, takes up reasonable disk space, and exports faster than other formats. If you're uploading to YouTube or social media, MP4 is the safest choice.

If you're editing the video further in another program, consider ProRes or DNxHD — these formats preserve more detail but create much larger files and take longer to export. Use them only if you know the next step requires it.

Avoid exporting to MOV unless you're working exclusively on Mac. Windows and Android devices often struggle to play MOV files smoothly.

Frequently Asked Questions

Can I slow down only part of a video?

Yes, but only in DaVinci Resolve or Adobe Premiere Pro. The built-in tools (Photos, iMovie, camera apps) apply one speed to the entire video. In DaVinci Resolve, split the clip where you want the speed change, then apply different speeds to each section.

What if my video looks blurry or choppy after I slow it down?

This usually means the original video was shot at 30fps or lower. Slowing it down too much makes the gaps between frames visible. Shoot at 60fps or higher if you plan to slow down in post-production. If you're stuck with 30fps footage, slow it down by no more than half speed.

Does slowing down a video make the file bigger?

Yes. A 30-second video slowed to half speed becomes 60 seconds long, so the file is roughly twice as large. The exact size depends on the resolution and quality settings you choose during export.

Can I undo the slow motion after I save it?

Not if you saved over the original file. Always use "Save a copy" or "Export" so the original stays untouched. If you need to go back, you'll have to re-edit from the original.

Which is faster to export, Windows or Mac?

Export speed depends on your processor, not your operating system. A newer Mac with an M-series chip exports faster than an older Windows computer with an older processor, and vice versa. The software matters too — DaVinci Resolve exports faster on Mac than on Windows for the same hardware.