How to Compress a Video (Free & Private, in Your Browser)

Step by step

1. Open the toolGo to Video Compressor — it runs in your browser, with no install or account.
2. Add your videoDrop in an MP4, MOV, or WebM clip. It is read locally and never uploaded.
3. Choose a qualityPick Smallest, Balanced, or High — and optionally downscale the resolution or turn on Trim to keep just part of the clip.
4. Compress and downloadClick Compress video, watch the progress, then preview and download the smaller MP4.

What actually makes a video smaller

Two things shrink a video: a lower bitrate (how much data each second of video uses) and a lower resolution (fewer pixels per frame). The quality setting controls the bitrate — Smallest saves the most, High keeps the most detail — and the resolution option lets you drop, say, a 4K clip to 1080p or 720p, which usually cuts the size a lot with little visible difference on a phone or laptop screen. Trimming to a shorter clip reduces it further.

Why do it in your browser instead of an upload site

Uploading a large video to a compression website is slow, and it hands your footage — which may be personal — to a third party. This tool re-encodes the video on your own device using your browser’s built-in codecs (WebCodecs), so nothing is uploaded and nothing is stored. It is also often faster, because there is no upload-then-download round trip.

What works best

It reads MP4, MOV, and WebM and always outputs an MP4 that plays everywhere. Use an up-to-date Chrome, Edge, or Safari, since compressing needs the browser’s video encoder; if the tool says your browser can’t re-encode, switch to one of those. Very large clips take longer to process, but they stay entirely on your device the whole time.