> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zevor.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Slow motion
> Turn any clip into smooth AI slow motion with frame-by-frame interpolation. No judder, no lost detail. Ideal for reels, intros, ads and sports clips.
Slow motion turns a regular-speed clip into a smooth slow-mo plate.
AI interpolates intermediate frames between your originals, so you
don't see the jumps or judder you get when you just slow a clip down
in an editor.
## What it's for
* Turn a phone recording (that wasn't shot in slow-mo) into a
cinematic plate.
* Highlight gestures, expressions or details that fly past at full
speed (bird wings, splashes, transitions).
* Intros and B-roll for reels where the slow pace is the "wow".
## How it works
MP4, any format (horizontal or vertical).
**2x** (half speed) or **4x** (quarter). 4x is very cinematic but
the clip lasts twice as long as 2x.
Runs in \~20-30 seconds. Download the final MP4, ready to post.
## Cost
| Source duration × factor | Approx cost |
| ------------------------ | ----------- |
| 4 s at 2x | 8 cr |
| 8 s at 2x | 16 cr |
| 4 s at 4x | 16 cr |
| 8 s at 4x | 32 cr |
Priced per second of the **source** (2 cr/s at 2x, 4 cr/s at 4x).
Higher factor costs more because we generate more frames.
## Best practices
* Start with **short** clips (3-6 s). 4x slow-mo on 6 s is already
24 s of output, plenty for a B-roll plate.
* **Steady camera** and **well-lit subject** pay off: interpolation
needs to see well to invent well.
* Pair with [Upscale video](/en/video-tools/upscale-video) if you
start from low resolution and want slow-mo AND sharpness.
## Limits
* No audio: the result comes muted. Add music or foley in your editor.
* MP4 only.
Try it: [zevor.ai/slow-motion-video](https://zevor.ai/slow-motion-video).