Documentation — CompressVideo.xyz

Getting Started

Select a video file: Open the video compressor and click the upload area on the home page or drag and drop a video file. Supported formats: MP4 MOV AVI MKV WebM. Maximum file size is 500 MB.
Choose compression level: High Quality — reduces file size by 40–60% with minimal visible quality change. Best for professional content.
Balanced — the best choice for most people. Good quality at a significantly smaller size.
Smallest File — maximum compression. Useful for messaging apps, email attachments, or previews.
Download your file: Once compression completes, the download button appears. Your compressed video is an MP4 file with H.264 video and AAC audio — compatible with all devices, apps and platforms.

Video codec: H.264 (libx264) — the most widely supported codec for web, mobile and social media playback.
Audio codec: AAC at 128 kbps — clear audio quality suitable for voice and music, compatible with all platforms.
Quality settings (CRF values): High Quality uses CRF 22, Balanced uses CRF 28, Smallest File uses CRF 35. Lower CRF = higher quality and larger file. FFmpeg's default is CRF 23.
Output format: Always MP4 with H.264 + AAC. Container format is optimised for fast web streaming (moov atom at the front of the file).
Processing engine: Videos are processed by FFmpeg running on a dedicated server. FFmpeg is an open-source, professional-grade video processing library used by YouTube, Netflix, Facebook and many others.

What happens to my video?: Your video is uploaded over HTTPS to our processing server, compressed, and made available for download. It is automatically deleted within one hour regardless of whether you download it or not.
Is my video stored permanently?: No. We do not retain, archive, or back up any video files. Temporary files are purged automatically and cannot be recovered after deletion.
Can anyone else download my compressed video?: No. Each compressed file is tied to a unique session token generated in your browser. Only the browser session that uploaded the video can download the result.
Do you collect any data?: We collect minimal anonymous usage statistics: total number of videos processed and total gigabytes saved. No IP addresses, file names or video content are logged or retained.

File size limit: 1 GB per video. If your file is larger, trim it first or split it into shorter segments.
One video at a time: Each IP address can process one video at a time. Once your compression is complete and downloaded, you can immediately compress another.
File expiry: Compressed files are available for download for up to one hour. After that they are permanently deleted from our server.
Supported browsers: Chrome 90+, Firefox 88+, Safari 14+, Edge 90+. Works on iPhone (Safari) and Android (Chrome). Internet Explorer is not supported.