Free tool · 100% in your browser
Video compressor
Shrink a video so it fits in Slack, email, or an issue tracker. Compression runs on your machine — nothing is uploaded.
Drop a video here or choose a file
MP4, WebM, or MOV · compression runs in real time on your machine
Frequently asked questions
Is my video uploaded to a server?
No. The re-encode runs entirely in your browser using its built-in media encoder. Your file never leaves your machine — which is also why there's no file-size limit tied to a pricing plan.
How much smaller will my video get?
Screen recordings compress extremely well because most of the frame doesn't change between frames. A raw 100MB screen capture typically lands between 10-30MB on the Balanced preset. Footage with lots of motion (games, camera video) compresses less.
Why does compression take as long as the video?
This tool re-encodes in real time by playing the video through your browser's encoder — a 60-second clip takes about 60 seconds. Keep the tab in the foreground while it runs.
Why is my output a .webm file?
The tool prefers MP4 when your browser's recorder supports it (recent Chrome does). Browsers that can't record MP4 fall back to WebM, which Slack, Discord, and Chrome-based apps all play natively. MP4/H.264 is still the compatibility master for demos and downloads; WebM is the right sibling for website embeds. If you need guaranteed MP4, a desktop tool re-encoding offline will serve you better.
Compressing a screen recording?
The best compression is a recording that's tight in the first place. ZoomCap records your Mac's screen, lets you trim dead air and speed up slow parts, and exports an efficient MP4 at 720p or 1080p — locally, like this tool. If you're choosing between MP4, MOV, and WebM before you compress, start with the 2026 video format comparison: H.264 in MP4 is still the compatibility master, and WebM is a sibling for website embeds — not a replacement you send everywhere.