Crop a video to a social-media format locally - portrait 9:16, square 1:1 or 4:5. Never leaves your device. No upload.
Running locally on your device ...
Running locally on your device ...
0%
Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Instagram Reels, TikTok and Stories want a tall 9:16 format, a feed post is often square (1:1) or a slightly taller 4:5 - a normally shot 16:9 video fits none of those without black bars. This tool crops your video locally to the chosen format instead of stretching it or adding bars.
The crop is always centered: if your video is wider than the target format, the sides are cut and the full height stays; if it is narrower/taller, the top and bottom are cut and the full width stays. There is currently no free positioning of the crop area - for a deliberately off-center subject (e.g. a person at the edge of the frame), use the sibling tool "Edit video", which offers more control.
Everything runs locally in the browser with mediabunny (MPL-2.0, self-hosted, no third-party CDN) on your browser's native WebCodecs encoder API. Your video is not uploaded.
| Input formats | MP4, M4V, WEBM, MOV, MKV |
|---|---|
| Output format | MP4 |
| Batch processing | No |
| Processing | Locally in your browser (WebCodecs) |
| File upload | None |
Limitations: The crop is always centered, with no free positioning. Audio is kept as long as the browser can encode a matching audio codec. It needs a modern browser with WebCodecs (recent Chrome, Edge or Safari); if that is missing, the tool says so honestly instead of silently doing nothing. Very large files (over 1 GB) are rejected (the browser tab's memory limit while streaming; without that support it is already about 600 MB).
| Format | Platform |
|---|---|
| Portrait 9:16 | Reels, TikTok, Stories |
| Square 1:1 | Feed |
| Portrait 4:5 | Feed |
No. The crop runs entirely locally in the browser; the video never leaves your device.
No, the crop is always centered. For a free position, use the sibling tool "Edit video".
A small, usual re-encoding loss is unavoidable because the video is recomposed.
A modern browser with WebCodecs (recent Chrome, Edge or Safari). If support is missing, you get a clear message.
Compress video · Convert video · Trim video · Edit video · Replace video audio · Burn in subtitles