Free Video Compressor — 100% In Your Browser
Powered by FFmpeg compiled to WebAssembly: your video never leaves your device. Choose quality, compress MP4/WebM/MOV, and download — the only major video compressor with true zero-upload.
🔒 100% Private — runs in your browser, nothing is uploadedHow to Use This Video Compressor (Step-by-Step)
- Pick a video — MP4, WebM or MOV.
- Choose quality — CRF 28 is a great default.
- Compress & download — first run loads the engine once; processing is fully local.
FFmpeg, compiled to WebAssembly — Under the Hood
FFmpeg is the battle-tested open-source encoder behind almost every video app. Compiled to WebAssembly it runs H.264 encoding inside your browser tab — slower than a native app, but with a huge advantage: your footage is never uploaded anywhere. CRF mode trades quality for size at a constant visual level instead of a fixed bitrate.
Frequently Asked Questions
Is there a file size limit?
Only your device memory — 1-2 GB videos work on a laptop; keep phones to shorter clips.
Why is the first run slow?
It downloads the ~30 MB FFmpeg engine once (cached after). Processing itself is local CPU.
Does any video go to a server?
No. FFmpeg runs entirely in your browser — this is the only zero-upload online video compressor.