Convert 15 fps video to 30 fps online. 30 fps is the NTSC and web standard used by most phones and social platforms. For real smoothness, enable motion interpolation — it generates new in-between frames instead of duplicating existing ones.
Two modes. Fast (default off): existing frames are duplicated to reach 30 fps — compatible, but motion looks the same. Motion-compensated interpolation: the converter analyses movement between your 15 fps frames and generates real new in-between frames — visibly smoother, like a TV's motion-smoothing, but rendered permanently into the file. 30 is exactly double 15, so every frame is repeated twice — a perfectly even cadence, no judder.
| Method | Frame duplication, or motion-compensated interpolation (real new frames) |
|---|---|
| Output | MP4 — H.264 video (CRF 20), AAC audio, web-optimized (faststart) |
| Duration & audio | Unchanged, stays in sync |
| Input formats | MP4, MOV, WebM, MKV, AVI… anything FFmpeg reads |
| Privacy | Processed on our server, auto-deleted after 1 hour, never shared |
Only with motion interpolation enabled — it generates real new in-between frames. Without it, frames are duplicated: the file plays at 30 fps but motion looks identical to the original.
No. Only the frames-per-second count changes. Duration is identical and audio is carried over in sync.
Upload mp4, mov, webm, mkv, avi… anything ffmpeg reads. You get back a widely compatible MP4 — H.264 video (CRF 20), AAC audio, web-optimized (faststart).
Yes — free, no signup, no watermark. Files up to 100 MB, deleted automatically after one hour.
Several times the clip's duration, depending on resolution — it computes motion for every generated frame. Plain duplication is usually faster than real time.