How to Make a Video Slow Motion in 2026: 7 Ways for Phone, Online & Desktop

Why Slow Motion Looks Choppy (and How to Fix It)

Here is the trap most people fall into. When you drag a speed slider down to 0.25x, the editor simply holds each original frame on screen longer. A 30fps clip slowed to 4x still only has 30 real frames per second of source motion spread across four times the runtime, so playback judders. There is no new information — just stretched-out old frames.

The fix is AI frame interpolation. Instead of repeating frames, interpolation analyzes the motion between two frames and generates realistic in-between frames, so the slowed clip plays at a genuinely higher frame rate. This is the single biggest reason two slow-motion videos of the same footage can look completely different. If you want the technical background, our roundup of AI frame interpolation software breaks down how the algorithms reconstruct motion, and this SmoothVideo Project review covers a popular open-source interpolation engine.

So before you pick a method below, decide how smooth you need the result to be. For quick social clips, a speed slider is fine. For dramatic 4x slow motion that has to look filmed, you want frame interpolation.

How to Make a Video Slow Motion on iPhone and Android

The fastest way to make a video slow motion is to record it that way in the first place.

On iPhone: Open the Camera app, swipe to Slo-Mo mode, and record. The iPhone captures at 120fps or 240fps, so playback is smooth by design. To slow existing footage instead, open the clip in Photos, tap Edit, and drag the vertical bars under the timeline to set which section plays slow.

On Android: Most Samsung, Pixel, and other flagship phones have a Slow motion or Super Slow-mo mode in the camera app. For clips you already shot, the built-in Google Photos or Gallery editor lets you adjust playback speed on a segment.

Phone methods are convenient but limited: they only interpolate footage you captured in slow-motion mode, and slowing a normal 30fps clip on-device still looks choppy. If you filmed at a standard frame rate and need it smooth, jump to the desktop AI method below, or first increase your video frame rate so there is more motion data to work with.

How to Make a Video Slow Motion Using UniFab Smoother AI (Best Pick)

UniFab Smoother AI uses deep-learning frame interpolation to generate brand-new frames between the ones you already have, producing slow-motion output that looks naturally filmed at a higher frame rate. Unlike a plain speed slider, it fills in the missing motion data, so the result stays smooth even at 4x slowdown — no choppy, stuttery playback.

Platform: Windows (desktop download) | Price: $44.99/month, $69.99/year, or $89.99 lifetime | Frame rate: boosts footage up to 120 FPS with AI Frame Interpolation.

Step-by-Step Guide

1. Download and install UniFab Smoother AI on your Windows PC, then launch it and open the Smoother module.
2. Click Add Video and import the clip you want to slow down (MP4 or MKV).
3. Choose your target frame rate (up to 120 FPS) and slow-motion level — 2x for a subtle effect, 4x for dramatic slow motion.
4. Pick an output folder and click Start. GPU acceleration processes the interpolation, and you get a smooth, artifact-free slow-motion file.

Why UniFab Smoother AI Stands Out

One honest limitation: UniFab Smoother AI is Windows-only and needs a desktop download, so Mac users and anyone who wants a purely in-browser tool should use one of the online options below.

How to Make a Video Slow Motion in CapCut

CapCut is the go-to editor for social creators and works on both mobile and desktop. To slow a clip: import your footage, tap it on the timeline, open Speed → Normal, and drag the slider below 1x. CapCut also has an Optical flow toggle under the speed settings that applies light frame blending for smoother results — turn it on for slow-motion shots. If you want a ready-made look, this slow-motion CapCut template lets you drop your clip into a pre-built speed ramp.

CapCut's optical flow helps, but it is not full AI interpolation, so extreme slowdowns on low-frame-rate footage can still soften or ghost. It is best for quick, stylized social edits rather than clean 4x cinematic slow motion.

How to Put a Video in Slow Motion Online

Online editors are handy when you need a quick edit without installing anything. Keep in mind that browser-based tools upload your footage to remote servers, which introduces latency, file-size limits, and privacy considerations, and most lack frame interpolation, batch processing, and GPU acceleration.

VEED.IO

VEED.IO turns any clip into a slow-motion video with an instant speed control that works in any web browser on any device. It gives you full control over the slowdown speed.

Platform: Web | Price: Lite $12/month, Pro $29/month

How to use VEED.IO for slow motion:

1. Go to veed.io and upload your video.
2. Click the clip on the timeline, then open Settings.
3. Scroll to Speed and drag the slider below 1x (e.g., 0.5x for half speed).
4. Preview the result and click Download.

VEED can split a clip to slow only a specific segment, supports AVI/MOV/MP4, and includes crop, trim, and subtitle tools. Its limitation: no frame interpolation, so lower speeds can look choppy, and there is no batch processing.

Canva

Canva lets you create a slow-motion clip on any device without a watermark, with a large stock library and social-ready templates. Open a Canva video project, upload or pick a clip, click it, select Playback, and move the speed slider left (minimum 0.25x), then download.

Platform: Web | Price: Pro $120/year

Canva is intuitive and template-rich, but has no AI frame interpolation — lower speeds look stuttery — and the free plan limits export resolution.

Kapwing

Kapwing is an installation-free online slow-motion maker that keeps decent quality and works across devices. Open Kapwing, upload your video or paste a URL, use the speed slider (0.25x to 4x) on the right panel, then Export Project at up to 4K.

Platform: Web | Price: Pro $24/month, Business $64/month

Kapwing exports up to 4K and has a wide speed range, but it has no frame interpolation, no batch processing, and the free plan adds a watermark.

How to Make Slow Motion in Premiere Pro

For professional editors, Adobe Premiere Pro produces high-quality slow motion using Optical Flow time interpolation. Right-click the clip, choose Speed/Duration, set the speed below 100% (for example 25%), then under Time Interpolation select Optical Flow and render. Optical Flow analyzes motion vectors to synthesize intermediate frames, so it looks far smoother than the default Frame Sampling. It is powerful but requires a Creative Cloud subscription, a capable machine, and render time — overkill for a quick clip but ideal for a finished project.

Desktop vs. Online Slow Motion Tools: Quick Comparison

UniFab Smoother AI leads this table because it is the only option here that uses true AI frame interpolation for smooth slow motion, but the online tools remain fine for casual edits.

Bottom line: if smooth, artifact-free slow motion is the priority, a desktop tool with AI frame interpolation delivers noticeably better results than speed-slider-only online editors. Online tools work fine for casual edits where minor choppiness is acceptable. For even more options across platforms and apps, see this slow motion video editor roundup.

Tips for Smoother Slow Motion Results

1. Shoot at a higher frame rate when possible. Footage recorded at 60fps or 120fps gives interpolation more data to work with than 24fps source material.
2. Keep the scene well-lit. Low light adds noise and motion blur, both of which degrade slow motion. Choosing the right video frame rate converter also helps you standardize footage before slowing it.
3. Use a tripod or stabilizer. Camera shake is magnified in slow motion, so stabilize before applying the effect.
4. Choose the right slowdown level. A 2x slowdown is subtle and natural; 4x is dramatic but needs more generated frames — match the level to your intent.
5. Export in a high-bitrate codec. Re-encoding at a higher bitrate preserves newly generated frames; H.265 (HEVC) offers the best quality-to-size ratio in 2026.
6. Enhance before you slow down. If your source is low-resolution, upscale first for the sharpest possible slow-motion output.

Frequently Asked Questions

How do I make a video slow motion on Windows?

Install UniFab Smoother AI on your Windows PC, open the Smoother module, import your video, choose a slow-motion level (2x or 4x) and a target frame rate up to 120 FPS, then click Start. Because it uses AI frame interpolation to generate new frames rather than stretching existing ones, the slowed clip stays smooth even at 4x. The whole process is essentially three steps: import, set speed, export.

How do I make a video slow motion on iPhone?

Open the Camera app and swipe to Slo-Mo mode to record at 120fps or 240fps, which is smooth by default. To slow footage you already shot, open it in Photos, tap Edit, and drag the vertical bars under the frame timeline to mark the segment you want slowed. Note that slowing a clip filmed at a normal 30fps on-device will still look choppy, since the phone has no extra frames to interpolate.

Can I put a video in slow motion online for free?

Yes. VEED.IO, Canva, and Kapwing all offer limited free tiers with speed adjustment — upload your clip, drag the speed slider below 1x, and export. Just know that free plans often add a watermark and none of them use frame interpolation, so at very low speeds the result may look stuttery. For consistently smooth slow motion without a watermark, a desktop tool with AI interpolation is the safer choice.

What is frame interpolation and why does it matter for slow motion?

Frame interpolation is an AI technique that generates new frames between existing ones. Without it, slowing a 30fps video to 4x simply repeats or stretches frames, which causes visible stutter. With interpolation, the software creates realistic in-between frames so playback stays fluid even at extreme slowdowns. It is the core reason UniFab Smoother AI produces smooth slow motion where a plain speed slider produces choppy results.

Desktop vs online slow motion tools — which is better?

Choose a desktop tool like UniFab Smoother AI when you need AI frame interpolation, batch processing, offline privacy, or 4K/120fps output — it delivers the smoothest slow motion. Choose an online editor such as VEED.IO, Canva, or Kapwing when you want a quick, one-off edit without installing software and small quality trade-offs are acceptable. In short: desktop for quality and volume, online for speed and convenience.

How much can I slow a video down without losing quality?

With AI frame interpolation, a 2x slowdown from 30fps source footage looks excellent, and a 4x slowdown holds up well when the source is 60fps or higher. Without interpolation, anything beyond 2x on a 30fps clip will show noticeable stutter because the editor is only repeating frames. Shooting at a higher frame rate to begin with always gives you more headroom for smooth slow motion.

Can I make a full-length movie slow motion?

Yes. Desktop tools like UniFab Smoother AI support batch processing and GPU acceleration, which makes it practical to process feature-length files in one queue. Online tools are generally limited to shorter clips because of upload-size caps and server-side processing constraints, so a movie-length project is better handled by a desktop application that works offline.

What video formats work best for slow motion editing?

MP4 (H.264 or H.265) and MKV are the most widely supported formats for slow motion. UniFab Smoother AI handles both natively for input and output. For online editors, MP4 is the safest choice because every major platform accepts it. If you have an unusual format, convert it to MP4 first to avoid upload or compatibility errors.

Does slowing a video affect the audio?

Yes. Slowing a video also stretches the audio, which lowers the pitch and extends the duration. Most editors either mute the audio during slow-motion segments or offer a separate audio-speed control. If clean sound matters, the simplest approach is to replace the soundtrack with music or a voiceover after you apply the slow-motion effect.

How much does UniFab Smoother AI cost?

UniFab Smoother AI is priced at $44.99 per month, $69.99 per year, or $89.99 for a lifetime license, and it runs on Windows. That covers the full AI frame interpolation engine, batch processing, GPU acceleration, and output up to 120 FPS. If you only need an occasional quick edit, a free online tier may be enough, but for repeated, smooth slow-motion work the desktop license pays off.