--- title: "Make a Video Slow Motion Online, Free | boomerang.video" description: "Slow a video down to 0.75×, 0.5× or 0.25× with smooth frame blending, keep or mute the sound, and download an MP4. Free in your browser, plus iPhone steps." url: https://boomerang.video/slow-motion-video --- Free · runs in your browser # Make a video slow motion Open any clip, pick how slow, and the preview plays it at that speed with blended frames so motion glides. Save an MP4 made on your own device, with no upload. To make a video slow motion, open it with **Choose a video** above. **Slow motion** is selected under **Make**, with **Speed** at 0.5× and **Smooth frames** on, and the preview plays it slowed straight away. Pick 0.25× or 0.75× if you prefer, then press **Export slow motion** and **Download MP4**. How smooth slow motion looks depends on how many frames the camera recorded. A clip filmed at 60 frames a second slowed to 0.5× still shows 30 real frames every second, so it looks completely fluid. A 30 fps phone clip at 0.5× only has 15 real frames a second; **Smooth frames** blends each pair of neighbours to fill the gaps, which hides most of the stepping. For a short slow-motion moment that plays forwards and back on a loop, use the [slow-motion boomerang maker](https://boomerang.video/slow-motion-boomerang) instead. ## How to slow down a video in 3 steps 1. ### Open the video Press **Choose a video** or drop the file on the page. The whole clip is selected, up to 30 seconds; drag the edges of the window on the **Pick the part** strip to slow only part of it. 2. ### Pick the speed Tap 0.75×, 0.5× or 0.25× under **Speed**, or drag the slider anywhere between 0.25× and 1×. Keep **Smooth frames** on unless the clip was filmed at 60 fps or more. 3. ### Export Press **Export slow motion**. When it’s ready, press **Download MP4**, or **Share or save to Photos** on a phone. ## How slow can a video go before it stutters? Divide the frame rate the clip was filmed at by how many times slower you want it. If the answer is 24 or more, the slow motion will look smooth on its own; below that, frame blending does the work. * **240 fps** (iPhone and many Android slow-motion modes): smooth at any speed here. * **120 fps**: smooth down to 0.25×. * **60 fps**: smooth at 0.5×; blending helps at 0.25×. * **30 fps** (most normal phone video): fine at 0.75×, good with blending at 0.5×, dreamy and soft at 0.25×. * **24 or 25 fps** (cameras and films): best kept at 0.5× or faster. This tool reads up to 60 frames a second from the clip and writes a 30 fps MP4, so at 0.5× a 60 fps clip uses every real frame. It can’t invent detail that wasn’t filmed: very fast movement filmed at 30 fps still blurs at 0.25×. ## Slow motion on iPhone: Slo-mo mode vs a normal video ### Filming in Slo-mo The Camera app’s **Slo-Mo** mode records at 120 or 240 frames a second. In Photos, open the video and tap **Edit**: the bar under the frames shows where it slows down, and you can drag its handles to change which part plays slowly. That’s the best quality you can get, but only for clips filmed that way. ### Slowing a normal video Photos can’t slow down a video that was filmed normally. Two free options: 1. In Safari, open this page, tap **Choose a video**, pick the clip, choose a speed and tap **Export slow motion**, then **Share or save to Photos**. 2. In iMovie for iPhone, add the clip to a movie project, tap it in the timeline, tap the speed button and drag the slider towards the tortoise (as slow as 1/8×). Then export the movie. Slo-mo clips from the Camera app also open here. They hold far more frames than a normal video (this tool reads up to 60 a second), so they slow down very cleanly. ## Slow down only part of a video The export contains only the section inside the window on the strip, slowed down. To keep the rest at normal speed (the sports-replay effect), export the slow part here and put it between the normal-speed parts in an editor such as iMovie, CapCut or Premiere Pro. For a slow part inside a looping clip, the [slow-motion boomerang](https://boomerang.video/slow-motion-boomerang) has a **Slow-mo section** that slows just the middle of the movement, both ways. To run footage backwards rather than slower, use the [video reverser](https://boomerang.video/reverse-video); its **Speed** setting also goes down to 0.5× for a slow reverse. ## Sound in slow motion **Sound** is off by default. When you turn it on, the audio slows with the picture, the way a tape played slowly does, so it also drops in pitch: an octave lower at 0.5×. That suits dramatic effects and engine noise; for voices or music, leave sound off and add a track in your editing app instead. ## Slow-motion video questions ### How do I make a video slow motion for free? Open it on this page, choose 0.75×, 0.5× or 0.25× under Speed and press Export slow motion. There is no account, watermark or upload: the video is processed in your browser. ### How do I turn a normal iPhone video into slow motion? The Photos app can only adjust videos filmed in Slo-mo. For a normal video, open this page in Safari, choose the clip and a speed, export it and save it to Photos, or use the speed control in iMovie for iPhone. ### What does Smooth frames do? When a slowed frame falls between two real frames, it mixes them in proportion instead of showing the same frame twice. Movement looks continuous rather than jerky, with slight softness on fast motion. ### How long can the slow-motion video be? Up to 30 seconds of the clip can be slowed at a time, and the result can last up to two minutes, so 0.25× works on clips up to 30 seconds. GIF and WebP exports are limited to 20 seconds. ### Does slowing a video down lower the quality? The resolution stays the same up to 1080p at Size Large. What changes is smoothness: a slowed 30 fps clip has fewer real frames per second, which Smooth frames softens. Footage filmed at 60 fps or more slows down with no loss of smoothness. ### Can I slow down a video and reverse it? Yes. Choose Reverse under Make and set Speed to 0.5×: the clip plays backwards at half speed. Turn on Smooth frames for a gliding result. ## More slow-motion and reverse guides * [ Boomerang video maker Pick a moment from any clip and bounce it forwards and back, in your browser. ](https://boomerang.video/) * [ Slow-motion boomerang maker Slow the whole bounce, or just the peak, with smooth frame blending. ](https://boomerang.video/slow-motion-boomerang) * [ Reverse a video online Play any clip backwards, whole or in part, with or without reversed sound. ](https://boomerang.video/reverse-video) * [ How to reverse a video on iPhone No reverse in Photos or iMovie: the free Safari method and the CapCut route. ](https://boomerang.video/reverse-video-iphone) * [ How to reverse a clip in Premiere Pro Speed/Duration → Reverse Speed, partial reverses, audio and smooth playback. ](https://boomerang.video/reverse-video-premiere-pro) * [ How to make a boomerang on iPhone Use the Live Photo Bounce effect in Photos, or bounce any video in Safari. ](https://boomerang.video/boomerang-on-iphone)