Why compress video
A modern phone records around 100 MB of footage per minute at 4K — far too large to email, share over chat, or upload to most CMS systems. A well-compressed copy of the same clip is typically under 20 MB with no visible quality loss. Compressing before sharing saves bandwidth, speeds up uploads, and stays inside the file-size limits that Slack, Discord, email, and most learning platforms enforce.
How this video compressor works
The tool runs ffmpeg.wasm directly in your browser tab. On the first run it downloads the WebAssembly build of ffmpeg (about 30 MB) and caches it; every subsequent compression uses the cached engine. Your video file is read into memory, re-encoded with the H.264 codec at the quality you pick, and written out as a standard MP4 that plays on every device and platform.
Picking a quality preset
Low uses constant-rate-factor (CRF) 32 — aggressive compression for sharing on chat platforms or as a small archive. Files are typically 70–85% smaller than the source. Medium (CRF 28, recommended) lands at 50–70% savings with no perceptible quality loss for the vast majority of footage. High (CRF 22) keeps the file near archival quality, useful for source masters you'll re-edit later.
Privacy by default
Every byte of the transcode happens locally in your browser. The video never leaves your device, so the compressor is safe to use for personal footage, client work under NDA, or anything else you wouldn't upload to a third-party server. The only thing we log is anonymous tool-visit counts, the same as every other page on the site.