Lower quality = smaller file. Medium is a good default.
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. 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 — 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.