PocketPlay
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Video Trimmer
Cut a video down to the part you want and optionally crop the frame — re-encoded in your browser, nothing uploaded.
Clip and crop
Drag a box on the picture to crop the frame. Leave it empty to keep the full frame.
Export
WebM export re-encodes in real time, so a 30-second clip takes about 30 seconds. WebM plays in every modern browser; use the MP4 button if you need a file for iPhone, Premiere or WeChat.
First use downloads the ffmpeg engine (about 30 MB) into this tab. It is cached until you reload.
Result
How to trim a video
- Drop your video on the box — it is opened straight from your disk and never uploaded.
- Drag the start and end sliders to the part you want to keep, and optionally drag a box on the picture to crop the frame.
- Click Trim and export WebM (or Export MP4) and download the finished clip.
FAQ
Why is the output a WebM file?
Browsers can only record video to WebM (VP9 or VP8 with Opus audio). WebM plays in Chrome, Edge, Firefox, Safari 15+, VLC and on Android. If you need MP4 for iPhone, Premiere or WeChat, use the MP4 button, which runs a real ffmpeg build compiled to WebAssembly inside the page.
Why does the export take as long as the clip?
The WebM export plays the clip through a canvas and records it in real time, so a 40-second selection takes about 40 seconds. The ffmpeg MP4 route can copy the streams without re-encoding, which is far faster — but only when you are not cropping or rescaling.
Does trimming lose quality?
The WebM path re-encodes, so there is a small generation loss; raising the bitrate to 5 or 8 Mbps makes it hard to see. The ffmpeg fast copy does not re-encode at all, so quality is identical, but the cut lands on the nearest keyframe rather than the exact millisecond.