Video Compressor & Trimmer

Drop a video, choose the part to keep, and the tool re-encodes it with your browser's own video encoder (WebCodecs) at the resolution and quality you pick. Three modes cover the usual jobs. Quality re-encodes at a low, medium or high quality level. Target size works out the bitrate that brings the clip in just under the number of megabytes you enter, handy for e-mail or chat limits. Trim only cuts the clip without re-encoding at all, which is fast and loses no quality. The video never leaves your device.

Re-encoded videos are saved as MP4 with H.264 when your browser can encode it (Chrome, Edge and Safari on most systems), which plays almost everywhere. Where H.264 encoding is not available, as in some Linux builds and Firefox, the tool falls back to WebM with VP9 and Opus and tells you so; every modern browser and VLC play it, though some older phones and editors do not. Lowering the resolution saves the most: 720p carries less than half the pixels of 1080p.

Trim only copies the compressed frames as they are, so a copy can only start on a key frame. An MP4 keeps the frames from that key frame but marks them to be skipped, so it still plays from your start; WebM has no way to mark them, so a WebM clip begins at the key frame, often a second or two before the point you chose. The result says which happened. For a frame-accurate cut, use one of the re-encoding modes. Target size is an estimate: encoders land close to the requested bitrate but can overshoot by a few percent on very busy scenes, and a size far below what the resolution needs gives a blocky picture. Long or 4K videos take a while and use a lot of memory; very large files may be beyond what a phone can handle. Reading and writing the MP4 and WebM files is done by the open-source Mediabunny library (MPL-2.0), which loads only when you open a video. When the first encode still comes out over the target, as happens with grainy or very busy footage, the tool encodes again with a lower bitrate and then a lower resolution, keeps the smallest result, and tells you if the target could not be met.