Converted locally — videos never leave your device
Updated July 2026
About this tool
Video file size is mostly a function of bitrate (how many bits the encoder spends per second), not resolution. This compressor re-encodes MP4, MOV, WebM or MKV video to H.264 with AAC audio at a lower bitrate, chosen from a quality preset computed for your clip's resolution and frame rate. Optionally it also downscales the resolution: 4K to 1080p is a big size win that's barely visible on most screens.
Phone and screen recordings are encoded at generous bitrates, so they typically shrink 50–90% with little visible change: enough to get a 200 MB clip under email attachment limits (~25 MB), into chat apps, or through an LMS upload cap. The same goes for a segment clipped from a YouTube video or any other screen capture. Everything runs locally on your device; if the result looks too soft, re-compress the original at a higher quality target rather than re-compressing the output.
Compression runs in a Web Worker in your browser. Videos are never uploaded.
Frequently asked questions
How does video compression work here?
The video is re-encoded to H.264 at a lower bitrate, and bitrate (not resolution) is what mostly determines file size. You can additionally downscale the resolution (say 4K to 1080p), which lets the encoder spend its bits on a smaller frame and shrinks the file further. Both run locally in your browser.
How much smaller will my video get?
Typically 50–90%. Phone and screen recordings are encoded at generous bitrates, so they compress dramatically with little visible change. A 200 MB phone clip often lands around 20–40 MB, small enough for email limits (~25 MB) and chat apps, while already-optimized web video shrinks less.
Will compression reduce quality?
Some information is always discarded (that's what makes the file smaller), but at moderate settings the difference is hard to see in normal playback. Fine textures and fast motion degrade first. If the result looks too soft, re-compress the original at a higher quality target rather than re-compressing the output.
Is there a file size limit, and are my videos uploaded?
Nothing is uploaded: compression runs entirely in your browser using its built-in codecs (WebCodecs), so private footage stays on your device. There is no server-imposed size cap either; very large files are limited only by your device's memory, and speed depends on your hardware and the video's length.