Video compressor

What it does with your clip

Before encoding, the service measures the clip: how much of the frame moves, how flat the picture is, how many frames are close to identical. It sorts the clip into one of four kinds and encodes each kind differently.

• Screen recordings with little movement are encoded fast at a conservative constant-quality setting, because flat areas compress very well.
• Mixed screen content, such as a recording with a webcam inset, gets a slower, more careful pass.
• Talking-head clips (a person against a mostly still background) use settings tuned for faces and steady backgrounds.
• High-motion footage, such as events, sport or film, keeps a higher bitrate ceiling so movement does not smear.

Resolution and frame rate

Frame rate and length are kept. Picture size is kept up to 1920×1080; anything larger, such as 4K, is scaled down to fit 1080p, which is where much of the saving on phone and camera footage comes from. Nothing is ever scaled up. A source that is already compressed efficiently may come back about the same size or slightly larger; the result card says so, and you should keep the original in that case.

What is checked before you can download

If a check fails, the job fails, you are not charged, and nothing is offered for download. The result card lists the checks that ran.

These checks are about timing and start-up behaviour. They do not compare audio streams or measure picture quality, so give a result a quick look and listen before you rely on it.

• The duration matches the original.
• The video is H.264 at a standard playback level.
• The first frame matches the original, so the file does not open on a black frame.
• The video starts at time zero, so chat apps do not show a black cover image.

Limits

Without an account you can compress 3 files a day, each up to 1 GB. With a verified email you get 10 files a day, each up to 5 GB. Beyond that, files use credits at one credit per gigabyte of source.