Free video compressor

What does a video compressor do?

A video compressor re-encodes a video so it takes fewer bytes, by lowering the bitrate, the resolution or both. You use one to reduce video file size for email and chat limits, faster uploads, smaller help-center pages and less storage. Screen recordings in particular often shrink a lot, because most of the screen doesn’t change from frame to frame.

This video compressor runs in your browser and uses its built-in video encoder, so a minute of 1080p video usually takes seconds. Your video never leaves your device.

Quality preset or target size?

The presets keep quality steady and let the size follow. A target size does the opposite. When the first pass comes out clearly over the target, the video is made again at a corrected bitrate, so the result lands near the target rather than exactly on it; aim a little below your limit. And if compressing would make a file larger than the original, you get the original back.

MP4 or WebM?

MP4 (H.264 video, AAC audio) plays almost everywhere: browsers, phones, Slack, email previews and video editors. The tool writes it with “fast start”, so it can begin playing on the web before it has fully downloaded. Choose MP4 unless you have a reason not to.

WebM (VP9 or VP8 video, Opus audio) is an open format for the web. It plays in current browsers but not in every app. Use it when a site asks for WebM.

How to compress an MP4 for a specific limit

1. Trim the start and end first. Seconds you don’t need are the cheapest bytes to save.
2. Resize if the video is larger than it will be shown: pick 1080p, 720p or 480p. A 4K screen recording watched in a help article rarely needs more than 1080p.
3. Mute it if the sound isn’t needed, or make it mono at a lower sound quality for speech. Audio takes part of every second’s budget.
4. Choose a target size in MB a little under the limit.
5. Watch the result. If text is too soft, shorten the clip or reduce the resolution instead of the quality.

Tips for screen recordings

Lower resolution beats lower quality

Small text suffers first when you squeeze bitrate. A clean 1080p file usually looks better than a blocky 4K file of the same size.

Use the screen recording preset

Interfaces don’t need 60 frames per second. The screen recording preset drops to 15, which keeps clicks and menus easy to follow and spends the saved bytes on sharp text. For videos with fast scrolling or animation, choose a quality preset and keep the original frame rate.

Don’t compress twice

Each re-encode loses detail. Compress from the original recording, not from an earlier compressed copy.

Keep the tab open

Your computer does the work inside the browser, so speed depends on your device: seconds for a short clip, a few minutes for a long recording on an older laptop. The tool shows progress and the time left.

Common mistakes

• Choosing the smallest preset for a tutorial, then finding the menu labels unreadable.
• Converting to WebM for a tool or device that only plays MP4.
• Setting a target size so low for a long video that the bitrate can’t carry the picture. Trim or resize first.

Why screen recordings compress so well

Video codecs store what changes between frames, not every frame in full. In a screen recording most of the screen stays still while a cursor moves or a menu opens, so there is little to store. That is why a long screen recording can shrink to a fraction of its size at the balanced preset, while camera footage of the same length shrinks far less. It also explains when compression struggles: scrolling long pages, playing video on screen or animated backgrounds change many pixels at once and need more bitrate to stay sharp. If a recording has a lot of scrolling, give it a higher quality preset or a larger target size.