Video Compressor
Reduce video file size without leaving your browser — private, free, powered by FFmpeg.
Your computer does 100% of the processing — not a server, not the cloud.
FFmpeg runs directly inside your browser via WebAssembly. Your video file never leaves your device. No upload, no cloud processing — your own CPU handles everything.
- ✓Files stay on your computer — zero upload, zero cloud
- ✓Completely private — no account, no logging of your files
- ✓Works offline once the engine has loaded
- ⚠Speed depends entirely on your device. Your CPU and RAM do all the work.
- ⚠Very large files (1 GB+) may be slow or use significant memory.
Drop a video here or browse files
MP4 · WebM · MOV · AVI · MKV · WMV and more
Recommended: under 500 MB for reasonable compression times
About the Video Compressor
This tool uses FFmpeg's H.264 encoder with CRF (Constant Rate Factor) — the industry-standard approach to quality-controlled video compression. A higher CRF means smaller files at the cost of quality; a lower CRF preserves more detail. Output is always MP4 for maximum compatibility.
How presets work
High Quality → CRF 20 (near-lossless, minimal reduction)
Balanced → CRF 28 (default — best general-purpose choice)
Small File → CRF 35 (visible at full screen, fine for sharing)
Tiny → CRF 42 (heavy compression, use for previews only)
Frequently asked
Is my video uploaded anywhere? No. FFmpeg runs inside your browser via WebAssembly. Your file never leaves your device.
Why does it take so long? H.264 encoding is CPU-intensive. Your machine does all the work, so speed depends entirely on your processor.
What's the output format? Always MP4 (H.264 + AAC) — the most universally compatible video format.
What if the compressed file is bigger? This can happen with very short clips or already-compressed videos. Try a lower quality preset or a resolution cap.