How to give phone video a 12 fps stop-motion look

You filmed a clip on your phone and you want the steady, stepped motion of stop-motion, the kind people call 12 frames a second. This guide covers what that number means, which camera settings are worth a look before you shoot, a command that does the timing, and a free web app with a 12 fps style.

What 12 fps means here

It is 12 different pictures every second, not 12 frames in the file. A phone clip is usually recorded at 24, 30 or 60 frames a second. To make it look like 12 fps stop-motion, you keep 12 of those pictures and show each one for more than a single frame. On a 24 fps clip, each picture is held for two frames. Animators call that shooting "on twos"; holding for three frames, which gives 8 pictures a second on a 24 fps clip, is "on threes". StopMo labels its presets the same way: Subtle is 12 frames a second and "smoother on twos", Classic is 8 and animated on threes, and Chaotic is 6.

Step 1: check the phone settings

Apple's article Change video recording settings on iPhone lists two settings that matter for this look. Both are under Settings > Camera > Record Video.

Auto FPS. The article says iPhone can improve video quality in low light by automatically reducing the frame rate to 24 fps, and that you can apply it to only 30 fps video, to both 30 and 60 fps video, or turn it off. A clip that changes frame rate partway is harder to step evenly, so turn it off if you want a steady rate.
HDR Video. On supported models iPhone records video in HDR and shares it with newer devices, while other devices receive an SDR version. You can turn HDR recording off here.

The frame rate itself is covered in Apple's separate article on video recording formats. These settings are for iPhone; check your own camera app on other phones.

Step 2, option A: hold the frames with ffmpeg

The free tool ffmpeg has an fps filter that converts a video to a specified constant frame rate by duplicating or dropping frames as necessary. Use it twice, first down, then back up to the clip's own rate:

24 fps clip, 12 pictures a second: ffmpeg -i in.mp4 -vf "fps=12,fps=24" out.mp4
30 fps clip, 15 pictures a second: fps=15,fps=30
60 fps clip, 20 pictures a second: fps=20,fps=60

We tested these on generated test clips. Each held every kept picture the expected number of times (24 fps to 12: 24 pictures in two seconds, each for 2 frames; 30 fps to 15: 30 pictures, each for 2 frames; 60 fps to 20: 40 pictures, each for 3 frames), and a clip with sound kept its sound. The catch is that the filter keeps whichever frame lands on each step. It does not pick the sharpest one, and it adds no shake, no flicker and no grain.

Step 2, option B: StopMo

StopMo is a free web application that turns a video clip into stop-motion, with no account and no watermark. You drop in a clip of up to 60 seconds (MP4, MOV or WEBM, up to 200 MB), pick the Subtle style for 12 frames a second, and watch a free live preview on your own clip before you render anything. Each preset can be fine-tuned.

Sharpest pose. It keeps the sharpest pose from each group of frames and holds it on twos or threes.
The handmade part. Every kept frame gets its own small shake and clay-like wobble, exposure flicker between shots, a colour grade, vignette and grain.
iPhone HDR. HDR clips from an iPhone are tone-mapped so they do not come out washed out.
Formats. Keep the original framing or crop to 9:16, 1:1, 4:5 or 16:9. The result is an H.264 MP4 with your original audio.

Good to know. Uploads and results delete themselves after 24 hours, and a result opens only with its private link. Full renders are limited to 10 an hour per visitor. It has not been tested on every phone browser. The AI styles are not on sale yet.

Disclosure. Atesen Software, which publishes this guide, makes StopMo. The ffmpeg route above works without it. For the whole look, see how to turn a video into stop-motion online.

Price. StopMo's stop-motion engine is free, with no sign-up and no watermark, limited to 10 full renders an hour per visitor. Paid passes for AI styles are being set up and are not on sale yet.

Open StopMo, free About StopMo

Which route fits

You only need the stepped timing, and a terminal is fine: ffmpeg.
You want 12 fps with shake, flicker, grain and a preview, from a phone clip: StopMo's Subtle style.
You want a rougher, choppier feel: StopMo's Classic (8) or Chaotic (6).

Atesen Software is independent. StopMo is independent and not affiliated with TikTok, Instagram, YouTube or any other video platform. Apple's iPhone guide and the ffmpeg documentation were checked on 22 October 2026; menus and options can change.

Questions about this guide: support@atesensoftware.com.